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Contract N°. Specific contract 185/PP/ENT/IMA/12/1110333-Lot 8 implementing FC ENTR/29/PP/FC Lot 2
Report
Preparatory Studies for Product Group in the
Ecodesign Working Plan 2012-2014:
Lot 8 - Power Cables DRAFT Task 1 report (2nd version)
Contact VITO: Paul Van Tichelen, www.erp4cables.net
Study for European Commission DG ENTR unit B1, contact: Cesar Santos Gil
2013/ETE/RTBD/DRAFT
Month Year
Draft version
Project team
Vito:
Paul, Van Tichelen
Dominic, Ectors
Marcel, Stevens
Karolien, Peeters
Disclaimer:
The authors accept no liability for any material or immaterial direct or indirect damage
resulting from the use of this report or its content.
The sole responsibility for the content of this report lies with the authors. It does not
necessarily reflect the opinion of the European Communities. The European Commission
is not responsible for any use that may be made of the information contained therein.
Distribution List
I
DISTRIBUTION LIST
Public
Executive Summary
II
EXECUTIVE SUMMARY
VITO is performing the preparatory study for the new upcoming eco-design directive for
Energy-related Products (ErP) related to power cables, on behalf of the European
Commission (more info http://ec.europa.eu/enterprise/policies/sustainable-
business/ecodesign/index_en.htm).
In order to improve the efficient use of resources and reduce the environmental
impacts of energy-related products the European Parliament and the Council have
adopted Directive 2009/125/EC (recast of Directive 2005/32/EC) establishing a
framework for setting Ecodesign requirements (e.g. energy efficiency) for energy-
related products in the residential, tertiary, and industrial sectors. It prevents disparate
national legislations on the environmental performance of these products from
becoming obstacles to the intra-EU trade. Moreover the Directive contributes to
sustainable development by increasing energy efficiency and the level of protection of
the environment, taking into account the whole life cycle cost. This should benefit both
businesses and consumers, by enhancing product quality and environmental protection
and by facilitating free movement of goods across the EU. It is also possible to
introduce binding information requirements for components and sub-assemblies.
The MEErP methodology (Methodology for the Eco-design of Energy-Related Products)
allows the evaluation of whether and to which extent various energy-related products
fulfil the criteria established by the ErP Directive for which implementing measures
might be considered. The MEErP model translates product specific information, covering
all stages of the life of the product, into environmental impacts (more info
http://ec.europa.eu/enterprise/policies/sustainable-
business/ecodesign/methodology/index_en.htm).
The tasks in the MEErP entail:
Task 1 - Scope (definitions, standards and legislation);
Task 2 – Markets (volumes and prices);
Task 3 – Users (product demand side);
Task 4 - Technologies (product supply side, includes both BAT and BNAT);
Task 5 – Environment & Economics (Base case LCA & LCC);
Task 6 – Design options;
Task 7 – Scenarios (Policy, scenario, impact and sensitivity analysis).
Tasks 1 to 4 can be performed in parallel, whereas 5, 6 and 7 are sequential.
Task 0 or a Quick-scan is optional to Task 1 for the case of large or inhomogeneous
product groups, where it is recommended to carry out a first product screening. The
objective is to re-group or narrow the product scope, as appropriate from an ecodesign
point of view, for the subsequent analysis in tasks 2-7.
The preparatory phase of this study is to collect data for input in the MEErP model. An
Executive Summary of the complete study will be elaborated at completion of the draft
final report.
Table of Contents
III
TABLE OF CONTENTS
Distribution List ................................................................................................I
Executive Summary ......................................................................................... II
Table of Contents .......................................................................................... III
List of Figures ................................................................................................ IV
List of Tables .................................................................................................... V
List of Acronyms ............................................................................................ VI
Task 1 - Scope ....................................................................... 10 CHAPTER 1
1.1 Product Scope ....................................................................................... 12
1.1.1 Key methodological issues related to the product scope definition ______ 12
1.1.2 Context of power cables within buildings and their electrical installation _ 15
1.1.3 First proposed scope of this study _______________________________ 20
1.1.4 Prodcom category or categories ________________________________ 22
1.1.5 Categories according to IEC, EN- or ISO-standard(s) ________________ 23
1.1.6 Other product-specific categories _______________________________ 24
1.1.7 Proposal for primary product performance parameter or ‘functional unit’ 25
1.1.8 Secondary product performance parameters ______________________ 25
1.1.9 First screening ______________________________________________ 32
1.2 Measurements/test standards .................................................................. 43
1.3 Existing legislation ................................................................................. 60
1.3.1 Key methodological issues related to existing legislation _____________ 60
Annex 1-A ...................................................................................................... 67
Annex 1-B ...................................................................................................... 74
List of Figures
IV
LIST OF FIGURES
Figure 1-1: A typical LV cable ............................................................................. 15 Figure 1-2: An armoured cable ............................................................................ 17 Figure 1-3: A shielded LV cable ........................................................................... 18 Figure 1-4: Simplified residential electrical diagram ............................................... 19 Figure 1-5: Simplified electrical diagram with 2 circuit levels ................................... 20 Figure 1-6: Peak-, r.m.s-, avg value of a sine wave ............................................... 30 Figure 1-7: Relationship between active-, reactive- and apparent power .................. 31 Figure 1-8: TN-S system with separate neutral conductor and protective conductor
throughout the system ................................................................................. 50 Figure 1-9: TT system with separate neutral conductor and protective conductor
throughout the installation ............................................................................ 51 Figure 1-10: IT system with all exposed-conductive-parts interconnected by a
protective conductor which is collectively earthed. ........................................... 52 Figure 1-11: Design procedure for an electric circuit .............................................. 57 Figure 1-12 example: two parallel circuits instead of one circuit .............................. 84
List of Tables
V
LIST OF TABLES
Table 1-1: Properties of Copper and Aluminium .................................................... 16 Table 1-2 ProdCom data .................................................................................... 22 Table 1-3: Application categories ........................................................................ 33 Table 1-4: Sales of power cables (kTon Copper).................................................... 34 Table 1-5: Stock of power cables (kTon of Copper)11 ............................................. 35 Table 1-6: Final affected energy demand, related to power cables13 ........................ 35 Table 1-7: Residential model: parameters and calculated losses (Note: these values are
updated in later chapters)............................................................................. 37 Table 1-8: Services model: parameters and calculated losses(Note: these values are
updated in later chapters)............................................................................. 38 Table 1-9: Impact on energy losses and copper usage (averaged over all models)21 .. 39 Table 1-10: Improvement scenario power cables .................................................. 40 Table 1-11 S+x scenario overview based upon CSA ratio (Note: these values are
updated in later chapters)............................................................................. 41 Table 1-12: Overview annual savings in 2030 (Note: these values are updated in later
chapters) .................................................................................................... 42 Table 1-13: Insulating compounds ...................................................................... 45 Table 1-14: Maximum resistance of class 1 solid conductors (IEC 60228:2004) ........ 47 Table 1-15: HD 60364-5-52:2011 minimum cross-sectional area ............................ 53 Table 1-16: Voltage drop values for lighting and other uses .................................... 54 Table 1-17: Cable designation system ................................................................. 54 Table 1-18: EU 28 National wiring codes .............................................................. 63 Table 1-19: Supply parameters and domestic installation practices per country ........ 67 Table 1-20: Losses in W/m for LV cables of class 1: circular, annealed copper
conductors: plain ......................................................................................... 75 Table 1-21: Losses in W/m for LV cables of class 1: circular, annealed copper
conductors: metal-coated ............................................................................. 76 Table 1-22: Losses in W/m for LV cables of class 1: Aluminium and aluminium alloy
conductors, circular or shaped ....................................................................... 77 Table 1-23: S+1 scenario ................................................................................... 78 Table 1-24: S+2 scenario ................................................................................... 79 Table 1-25: S+3 scenario ................................................................................... 80 Table 1-26: S+x scenario overview ..................................................................... 81 Table 1-27: S+x scenario overview based upon CSA ratio ...................................... 81 Table 1-28: Conductor volume increase based upon CSA ratio ................................ 82 Table 1-29: Loss reduction per conductor volume increase ..................................... 83
List of Acronyms
VI
LIST OF ACRONYMS
A Ampere
AC Alternating Current
Al Aluminium
AREI Algemeen Reglement op de Elektrische Installaties
ASTM
ATEX
avg
American Society for Testing and Materials
ATmosphères EXplosibles
Average
B2B Business–to-business
BAT Best Available Technology
BAU Business As Usual
BNAT Best Not yet Available Technology
BS
CE
British Standard
Conformité Européenne
CEN European Committee for Normalisation
CENELEC European Committee for Electro technical Standardization
CPD Construction Products Directive
CPR Construction Products Regulation
CSA Conductor Cross-Sectional Area
Cu Copper
Cu-ETP
Cu-OF
CO2
DALI
DC
Copper- Electrolytic Tough Pitch
Copper – Oxygen Free
Carbon Dioxide
Digital Addressable Lighting Interface
Direct Current
DIN Deutsches Institut für Normung
E Energy
EC European Commission
EEE
EMC
Electrical and Electronic Equipment
Electro Magnetic Compatibility
EMI Electromagnetic Interference
EMS Energy Management System
EN European Norm
EOL End Of Life
EPBD Energy Performance of Buildings Directive
EPR Ethylene Propylene Rubber
ErP Energy related Products
EuP Energy using Products
EU European Union
HD Harmonization Document
HV
Hz
I
IACS
Iav
High Voltage
Hertz
Current
International Annealed Copper Standard
Average Current
IEC
IEV
The International Electro technical Commission
International Electrotechnical Vocabulary
INDL
IT
INDustry Level
Information Technology
k
kg
Kd
kilo (10³)
Kilogram
Distribution factor
Kf Load form factor
List of Acronyms
VII
Kt
kWh
L
LCA
Temperature correction factor
KiloWatt hour
Length
Life Cycle Assessment
LF
LV
Load Factor
Low Voltage
LVD Low Voltage Directive
MEErP Methodology for Ecodesign of Energy related Products
MEEuP Methodology for Ecodesign of Energy using Products
MS
MV
Mega Siemens
Medium Voltage
NACE
NBN
NEN
NF
P
Nomenclature statistique des activités économiques dans la Communauté
européenne - Statistical classification of economic activities in the
European Community
Bureau voor Normalisatie - Bureau de Normalisation
NEderlandse Norm
Norm France
Power
PE Polyethylene
PEP
PF
Product Environmental Profile
Power factor
PJ
PP
Peta Joule
Polypropylene
PRODCOM PRODuction COMmunautaire
PV
PVC
PhotoVoltaic
Polyvinylchloride
R Resistance
R20
RCD
Resistance at 20°C
Residual Current Device
REMODECE Residential Monitoring to Decrease Energy Use and Carbon Emissions in
Europe
RES Renewable Energy Sources
r.m.s Root Mean Square
RoHS Restriction of the use of certain Hazardous Substances in electrical and
electronic equipment
S Apparent power
S Nominal cross sectional area of a conductor
SERL
SME
SERvices Level
Small and Medium sized Enterprise
TBC To Be Completed
TBD To Be Defined
TC Technical Committee
TR Technical Report
TWh
UK
Terra Watthour
United Kingdom
V Volt
VA
VDE
VITO
Volt Ampere
Verband der Elektrotechnik und Elektronik
Flemish institute for Technological Research
W
WEEE
Watt
Waste Electrical and Electronic Equipment
XLPE Cross-linked Polyethene
XLPVC Cross-linked PVC
List of Acronyms
VIII
Use of text background colours
Blue: draft text
Yellow: text requires attention to be commented
Green: text changed in the last update
List of Acronyms
IX
List of Acronyms
10
TASK 1 - SCOPE CHAPTER 1
Objective: This task classifies and defines the energy-related product group power
cables and sets the scene for the rest of the tasks. The product classification and
definition should be relevant from a technical, functional, economic and environmental
point of view, so that it can be used as a basis for the whole study.
It is important to define the products as placed on the Community market. This task
consists of categorization of power cables according to Prodcom categories (used in
Eurostat) and to other schemes (e.g. EN standards), description of relevant definitions
and of the overlaps with the Prodcom classification categories, scope definition, and
identification of key parameters for the selection of relevant products to perform
detailed analysis and assessment during the next steps of the study. This task will also
classify power cables into appropriate product categories while providing a first
screening or quick-scan of the volume of sales and stock and environmental impact for
these products.
Further, harmonized test standards and additional sector-specific procedures for
product-testing will be identified and discussed, covering the test protocols for:
• Primary and secondary functional performance parameters (Functional Unit);
• Resource use (energy, etc.) during product-life;
• Safety (electricity, EMC, stability of the product, etc.);
• Other product specific test procedures.
Finally, this task will identify existing legislations, voluntary agreements, and labelling
initiatives at the EU level, in the Member States, and in the countries outside the EU.
Summary of Task 1:
In brief the scope of the study is: ’losses in installed power cables in buildings’,
the power cable being the product put into service by the electrical installer in a circuit
of an electrical installation in a building. The electrical installation is proposed to
consider at system and/or extended product scope level, meaning that it will be
analysed at the level needed related to cable losses.
The electrical installation is taken into account as a system. In this context the
proposed primary functional performance parameter is ’current-carrying capacity’.
Losses in installed power cables in buildings are directly related to the loading.
Therefore nine functional categories of cable circuits were defined,
i.e. ’lighting’, ’socket-outlet’ and ’dedicated’ circuits in the ‘residential’, the ‘services’
and the ‘industry’ sector.
A first screening estimated losses in the services and industry sector about 2% while
losses in the residential sector seems to be much lower (<0.3%). This is because
circuits in residential buildings are in general much shorter and have relative low
loading. Therefore it is proposed to focus in the subsequent tasks on the services and
industry sector circuits.
Relevant standards, definitions, regulations, voluntary agreements and commercial
agreements on EU, MS and 3rd country level are part of this task report. Important
11
secondary performance parameters are the ‘Nominal Cross-Sectional Area (CSA)’ and
its corresponding ‘maximum DC resistance at 20°C (R20)’, which are defined in
standard IEC 60228. For the performance electrical installation codes play an important
role and they can differ per member state.
Comment: This report is currently a working progress, as some parts of the
study are missing comments and data from the stakeholders, therefore it shall
not be viewed as a full report.
List of Acronyms
12
1.1 Product Scope
1.1.1 Key methodological issues related to the product scope definition
In this task the classification and definition of the products should be based notably on
the following categorizations:
Prodcom category or categories (Eurostat);
Categories according to EN- or ISO-standard(s);
Other product-specific categories (e.g. labelling, sector-specific categories), if
not defined by the above.
Prodcom should be the first basis for defining the products, since Prodcom allows for
precise and reliable calculation of trade and sales volumes (Task 2).
If the proposed product classification and definition relevant from a technical, economic
and environmental point of view does not match directly with one or several Prodcom
categories, the study should detail how the proposed product categories are mapped to
the Prodcom categories or the other categories mentioned above.
In particular customer-made products, business-to-business (B2B) products or systems
incorporating several products may not match with Prodcom categories. In these cases,
the standalone or packaged products placed on the European internal market, to which
a CE mark is/could be affixed, should be defined. This may result in several Prodcom or
otherwise categorised products relevant for power cables.
The above existing categorizations are a starting point for classifying and defining the
products and can be completed or refined by other relevant criteria, according notably
to the functionality of the product, its environmental characteristics and the structure of
the market where the product is placed. In particular, the classification and definition of
the products should be linked to the assessment of the primary product performance
parameter (the "functional unit").
If needed, a further segmentation can be applied on the basis of secondary product
performance parameters. This segmentation is based on functional performance
characteristics, and not on technology.
Where relevant, a description of the energy systems affected by the energy-related
products will be included, as this may influence the definition of the proposed product
scope.
The resulting product classification and definition should be confirmed by a first
screening of the volume of sales and trade, environmental impact and potential for
improvement of the products as referred to in Article 15 of the Ecodesign Directive.
Also information on standards, regulations, voluntary agreements and commercial
agreements on EU, MS and 3rd country level should be considered when defining the
product(s) (section 1.3.1).
13
1.1.1.1 Important definitions and terminology in electrical installations
Important definitions and terminology in electrical installations (IEC 60050, IEC
Electropedia Area 461) are:
Low Voltage (IEV 601-01-26 / Fr: basse tension / De: Niederspannung): a set of
voltage levels used for the distribution of electricity and whose upper limit is
generally accepted to be 1 000 V a.c;
Electrical installation (IEV 826-10-01 / Fr: installation électrique / De:
elektrische Anlage): assembly of associated electric equipment having co-
ordinated characteristics to fulfil specific purposes;
(Electric) circuit (of an electrical installation) (IEV 826-14-01 / Fr: circuit
(électrique) (d'installation électrique) / De: Stromkreis (einer elektrischen
Anlage)): assembly of electric equipment of the electrical installation protected
against overcurrents by the same protective device(s);
Cable (IEV 151-12-38 / Fr: cable / De: Kabel): assembly of one or more
conductors (and/or optical fibres), with a protective covering and possibly filling,
insulating and protective material;
Cord (IEV 461-06-15 / Fr: cordon / De: schnur): flexible cable with a limited
number of conductors of small cross-sectional area;
Core (or insulated conductor) (IEV 461-04-04 / Fr: conducteur (isolé) / De:
ader): assembly comprising a conductor with its own insulation (and screens if
any);
Conductor (of a cable) (IEV 461-01-01 / Fr: conducteur (d'un câble) / De: Leiter
(eines kabel): conductive part intended to carry a specified electric current;
Wire (IEV 151-12-28 / Fr: File / De: draht): flexible cylindrical conductor, with
or without an insulating covering, the length of which is large with respect to its
cross-sectional dimensions
Note – The cross-section of a wire may have any shape, but the term "wire" is
not generally used for ribbons or tapes;
Socket-outlet (IEV 442-03-02 / Fr: socle de prise de courant/ De: Steckdose):
an accessory having socket-contacts designed to engage with the pins of a plug
and having terminals for the connection of cables or cords;
Circuit-breaker (IEV 441-14-20 / Fr: disjoncteur / De: Leistungsschalter): a
mechanical switching device, capable of making, carrying and breaking currents
under normal circuit conditions and also making, carrying for a specified time
and breaking currents under specified abnormal circuit conditions such as those
of short circuit;
Flexible conductor (IEC Electropedia Area: 461): stranded conductor having
wires of diameters small enough and so assembled that the conductor is suitable
for use in a flexible cable;
Insulated cable (IEC Electropedia Area: 461): assembly consisting of:
o one or more cores,
o their covering(s) (if any),
o assembly protection (if any),
List of Acronyms
14
o protective covering(s) (if any).
Note – Additional uninsulated conductor(s) may be included in the cable;
Insulation of a cable (IEC Electropedia Area: 461): assembly of insulating
materials incorporated in a cable with the specific function of withstanding
voltage;
Screen of a cable (IEC Electropedia Area: 461): conducting layer or assembly of
conducting layers having the function of control of the electric field within the
insulation.
Note – It may also provide smooth surfaces at the boundaries of the insulation
and assist in the elimination of spaces at these boundaries;
Shaped conductor (IEC Electropedia Area: 461): conductor the cross-section of
which is other than circular;
Armour (IEC Electropedia Area: 461): covering consisting of a metal tape(s) or
wires, generally used to protect the cable from external mechanical effects;
Sheath/jacket (North America) (IEC Electropedia Area: 461): uniform and
continuous tubular covering of metallic or non-metallic material, generally
extruded
Note – The term sheath is only used for metallic coverings in North America,
whereas the term jacket is used for non-metallic coverings;
Shielding conductor (IEC Electropedia Area: 461): separate conductor or single-
core cable laid parallel to a cable or cable circuit and itself forming part of a
closed circuit in which induced currents may flow whose magnetic field will
oppose the field caused by the current in the cable(s);
Shield of a cable (IEC Electropedia Area: 461): surrounding earthed metallic
layer which serves to confine the electric field within the cable and/or to protect
the cable from external electrical influence
Note 1 – Metallic sheaths, foils, braids, armours and earthed concentric
conductors may also serve as shields.
Note 2 – In French, the term "blindage" may be used when the main purpose of
the screen is the protection from external electrical influence;
Single-conductor cable or single-core cable (IEC Electropedia Area: 461): cable
having only one core;
Note – The French term «câble unipolaire» is more specifically used to designate
the cable constituting one of the phases of a multiphase system;
Solid conductor (IEC Electropedia Area: 461): conductor consisting of a single
wire;
Note – The solid conductor may be circular or shaped;
Stranded conductor (IEC Electropedia Area: 461): conductor consisting of a
number of individual wires or strands all or some of which generally have a
helical form.
Note 1 – The cross section of a stranded conductor may be circular or otherwise
shaped.
Note 2 – The term “strand” is also used to designate a single wire;
Wire strand (IEC Electropedia Area: 461): one of the individual wires used in the
manufacture of a stranded conductor.
15
1.1.2 Context of power cables within buildings and their electrical
installation
Power cables are used to transport electrical power either inside buildings or in
electrical distribution grids outdoor.
This study will focus on electrical installations within buildings and behind the
electrical meter. This is in line with the working plan 2012-20141 and the Consultation
Forum (CF-2012-02-EC) regarding power cables. In the working plan and at the
Consultation Forum (CF-2012-02-EC) it was explained that this product group concerns
cables within domestic and industrial buildings. A rationale for this is that electrical
distribution and transmission networks are another market segment with other
functional product requirements and players. Cables in distribution are a product group
very close to power transformers who are already advanced within the ErP directive2
process.
Power cables within buildings can be clearly separated from distribution power cables
by product related standards, primarily by its voltage, but also by earthing and
electrical armour requirements. Voltage levels used in electrical power cables are:
High Voltage (HV): voltage whose nominal r.m.s. value lies above 35kV
Medium Voltage (MV): voltage whose nominal r.m.s. value lies above 1kV and
below 35 kV (EN 50160)
Low Voltage (LV): voltage with a maximum of 1000Vac (IEV 601-01-26 /
EN50160).
Low voltage (LV) being the scope of the end application within electrical power
installations within buildings and therefore defining the proposed scope of this study.
Different parts of a LV power cable
Basically a cable consists of one or more conductors (a “core” is an insulated conductor),
insulation material of the conductors, an inner sheath and an over sheath (Figure 1-1).
Figure 1-1: A typical LV cable
Depending on the application (installation method, voltage level, environmental
conditions…) an additional mechanical protective cover (armour) and/or an electrical
shield can be present (Figure 1-2).
1 http://ec.europa.eu/enterprise/policies/sustainable-business/documents/eco-design/working-plan/ 2 http://ec.europa.eu/enterprise/policies/sustainable-business/ecodesign/product-
groups/index_en.htm
1 2 3 4 1. Solid Copper conductor
2. Insulation of the conductor
3. Inner sheath 4. Over sheath
List of Acronyms
16
Conductor
Insulation
Filler
Inner sheath
Shield
Oversheath/outer sheath
Figure 1-2: Different parts of a LV cable
The different parts of a typical LV cable are:
Conductor: conductive part intended to carry a specified electric current (IEV
461-01-01). The basic material of the conductor is copper or aluminium. The
conductor can be solid or flexible, depending on the application. Copper has a
higher electrical conductivity than aluminium, aluminium has a lower weight
density (see Table 1). Copper is the most used conductive material in wirings in
buildings whereas aluminium is e.g. most used for overhead lines. A LV cables
may contain one or more conductors (cores): earthing conductor, phase
conductors, neutral conductor). The earthing conductor is sometimes not
present in the electrical distribution, for example when TT earthing systems are
used.
Table 1-1: Properties of Copper and Aluminium
Property Copper (Cu-ETP) Aluminium (1350)
Electrical conductivity at 20°C
[MS/m] / [% IACS3] 58 / 100 35 / 61
Thermal conductivity at 20°C
[W/mK] 397 230
Density
[g/cm³] 8.91 2.7
Insulation : assembly of insulating materials incorporated in a cable with the
specific function of withstanding voltage (IEV 461-02-01). Insulation material
can consist of thermoplastic compounds such as PVC (Poly Vynil Chloride), PE
(Polyethylene); thermosetting compounds such as XLPE (Cross-linked
Polyethylene), EPR (Ethylene Propylene Rubber) or other synthetic or natural
materials.
3 IACS: International Annealed Copper Standard
17
Filler: This material is used in multi conductor cables to occupy interstices
between insulated conductors. The filler material shall be suitable for the
operating temperature of the cable and compatible with the insulating material.
Sheath: Uniform and continuous tubular covering of metallic or non-metallic
material, generally extruded (IEV 461-05-03). PVC (Poly Vynil Chloride), PE
(Polyethylene); thermosetting compounds such as XLPE (Cross-linked
Polyethylene), EPR (Ethylene Propylene Rubber) or commonly used.
Armour (Protective cover): covering consisting of a metal tape(s) or wires,
generally used to protect the cable from external mechanical effects (IEV 461-
05-06) (see Figure 1-2). This is not often used in electrical power cables within
buildings, it is mainly used in outdoor cables and in Low Voltage IT earthing
systems e.g. Norway4.
Figure 1-2: An armoured cable
Shield (of a cable) (Figure 1-3): surrounding earthed metallic layer which serves
to confine the electric field within the cable and/or to protect the cable from
external electrical influence (IEV-461-03-04). This is a commonly used cable in
industry (e.g. in areas with Electro Magnetic Interferences). Sometimes this
cable is also used in residential buildings e.g. Sweden (Europacable)
4 See comments Europacable – first stakeholder meeting
Shield
List of Acronyms
18
Figure 1-3: A shielded LV cable
Copper is the most used conductive material in wirings in buildings. Besides the
electrical losses, the use of copper, the insulation material and the method of
installation are the most significant environmental aspects related to power cables.
Electrical losses in power cables
Cable electrical losses are determined by Ohm’s law of physics and are also called Joule
losses. The magnitude of these losses increases with the square of the load current and
is proportional to the cable electrical resistance. As a consequence without loading
there are no cable losses, hence the entire electrical installation system (e.g. way of
installation, load of the cable, duration of use, interfaces with a variety of electrical
equipment) needs to be considered. For instance there is a relation between the total
cable losses in an electrical installation and the topology of the electrical installation.
When designing circuits for lighting three different topologies are commonly used:
Bus approach (e.g. DALI), where the switching is done near the lighting point by
means of a local relay
Relays (interrupters) located in the distribution board resulting in a star topology
Traditional wiring, by means of a mechanical switch connected to the lighting
point
The amount of cable used in an electrical installation depends among others on the kind
of topology that is applied. A star topology, connecting each individual appliance to a
central point by a dedicated cable, will increase the total length of cable used in the
installation. The average load per cable decreases compared to a traditional or bus
topology, therefore cables with a smaller CSA could be used. In practice however, the
same cable sections are used as in other topologies, unless the electrical installation
design is calculated.
Electrical installations in buildings
Electrical installations in buildings are defined by the international standard IEC 60364
series and fixed wiring products (cables) in the standards IEC 60227 and IEC 60245.
Electrical installation rules at EU member state level are in general according to these
international and European standards, however there may exist deviations and/or
additional requirements at member state level. The above mentioned standards are
primarily concerned with safety aspects of the electrical installation. However cables
with cross section areas beyond what is required for safe installations could lead to a
more economic operation and energy savings.
Cables are part of electrical circuits in electrical installations. The current-carrying
capacity is limited by circuit breakers because of safety reasons. Electrical circuits can
have socket-outlets or can be directly connected to loads, e.g. for lighting. The power
electrical installation system is typically described with a so-called ‘One-line diagram’5.
Examples of one-line diagrams of electrical circuits with typical IEC component symbols
are included in Figure 1-4 and Figure 1-5. The latter is a two-level electrical circuit,
meaning that there is a main distribution board with circuit breakers and a second-level
distribution board(box) with circuit breakers directly connected to the loads.
5 http://en.wikipedia.org/wiki/One-line_diagram
19
20 A
2P
X
3G2,5mm ²
20 A
2P
3
20 A
2P
3
2P
10 A
2P
3
3x1,5mm²
20 A
3
3G2,5mm²
25 A 5G4mm ²
4P
Mixed circuit
Socket outlets
1
1 2
3
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7
Δ300 mA
(4x10mm²)
3x400V + N
3 4 5 6 72
Socket outlets
20 A
BOILER
(1,8 kW)
PE
Δ30 mA 20 A
3
3 x 2,5mm²
1 2 3
OVEN
FURNACE
(8kWmax)
Light circuit
Socket outlets
(Bath room)
20 A
3Washing machine
3 x 2,5mm²
3 x 2,5mm²
3 x 2,5mm²
TO LV FEEDER
2P
kWh
OUTSIDE
INSIDE
Figure 1-4: Simplified residential electrical diagram
List of Acronyms
20
Figure 1-5: Simplified electrical diagram with 2 circuit levels
1.1.3 First proposed scope of this study
Given the context (see 1.1.2) the scope proposal is in summary: ’losses in installed
power cables in buildings after the meter’ taking into account the electrical
installation as a system, the power cable being the product put into service by the
electrical installer in a circuit of an electrical installation in a building.
The electrical installation including loads are taken into account at system level, this is
explained in more detail in chapter 3 amongst others it means that the installation will
be analysed at the level needed related to cable losses.
More in detail, the scope of this study “losses in installed power cables in buildings”
covers Low Voltage power cables for fixed wiring used in indoor electrical installations
in:
Residential buildings;
Non-residential buildings:
The non-residential buildings can be further categorised as follow (Ecofys6):
- Public/commercial buildings:
o Trade facilities: Trade, retail, wholesale, mall
o Gastronomic facilities: Hotels, restaurants, pubs, café’s…
o Health facilities: Hospitals, surgeries,..
o Educational facilities: Schools, colleges, academies, universities,
nurseries,..
6 Ecofys report, Panorama of the European non-residential construction sector, 9 December 2011
21
o Offices
o Other buildings: Warehouses, recreation facilities…
- Industrial buildings: factories, workshops, distribution centres….
Remarks:
Industrial buildings can consist of production halls and attached or detached
offices. Both are in the scope of this study;
Process installations which are in general outdoor installations are out of the
scope.
Practically, the scope includes low voltage cables on the customer side of the electricity
meter (utility cables are out of the scope) inside the above mentioned buildings. These
cables can be single core or multicore, shielded…. depending on the application and on
the European and National wiring regulations.
Explanation of the terms used in the scope:
“Low voltage”: voltage with a maximum of 1000Vac (IEV 601-01-26). In Europe
the standard nominal voltage for public Low Voltage is Un=230Vac r.m.s with a
maximum variation of + 10% (see EN 50160). For four wire LV distributions
systems the voltage between phase and neutral is 230Vac r.m.s and 400Vac
r.m.s between 2 phases.
“Fixed wiring”: refer to the method of installation of the (single core) cable in
the building e.g. enclosed in conduit, installed on a cable tray, cable trunking,
cable ladder…. (see IEC 60364-5-52, Table A.52.3)
“Insulated cables”: assembly consisting of:
o one or more cores,
o their individual covering(s) (if any),
o assembly protection (if any),
o protective covering(s) (if any).
Note – Additional un-insulated conductor(s) may be included in the cable
“Single core cables”: cable having only one core
o Note – The French term «câble unipolaire» is more specifically used to
designate the cable constituting one of the phases of a multiphase
system.
Remark: Further in this study the word “power cables” will be used as a general term
for single core or multi-core power cables, unless otherwise stated.
Out of the scope:
Losses in circuit breakers;
Losses or inefficiency in the loads connected to the circuit;
Losses due to poor connections (“A recent study found that average electrical
distribution system losses accounted for 2% of a plant’s annual energy use.
Losses due to poor connections represented one-third of these losses and
accounted for 40% of the savings after corrective actions were taken. (Source:
U.S. Department of Energy”)7;
Utility cables for transmission (HV) and distribution (MV,LV) of electrical energy;
Power cables for Nuclear power plants (require higher-quality cables that meet
stringent Nuclear Regulatory Commission standards);
7 ECI Publication No Cu0192: APPLICATION NOTE INFRARED SCANNING FOR ENERGY EFFICIENCY ASSESSMENT -Paul De Potter - January 2014
List of Acronyms
22
Power cables for hazardous locations (in ATEX zones);
Cables used for PV power plant, Wind power plant, ….;
Outdoor cables: Cables used in process installations (e.g. chemical and
petrochemical plants), railway cables,..;
Cables for mobile applications: (electric) cars, ships, metro, …
Busbar Trunking systems;
Outside of the scope of Tasks 1-6, but in the scope of Task 7 for a review on
potential negative impact related to proposed policy measures (if applicable):
Some of the installation cables included in the scope of this study are also used
in other sectors like machinery construction for wiring inside machines.
Measures on product level could as such have an impact on machine
construction.
Socket-outlets, junction boxes, cable installation systems (ducting systems,
trunking systems..), cable accessories,…,
Building design and construction
LV distribution board
Outside of the scope of Tasks 1-6, but in the scope of Task 7 for review on
potential loopholes related to proposed policy measures (if applicable):
utility cables, be it low Voltage, Medium Voltage and High Voltage utility cables,
all the cables with a rated voltage above 1000Vac r.m.s,
extra Low voltage (e.g. 24Vdc/ac; 12Vac…) cables,
connection of the electrical distribution board of the building to the LV
distribution grid (via a buried or overhead cable),
the electrical distribution boards, internal wiring in the distribution boards,
(smart) KWh-meter, RCD… ,
data cables (Ethernet cable, TV ..), telephone cables, lift cables, safety cables
(fire alarm..), , welding cables, instrumentation cable,… In general these are
special purpose power cables which are not fixed wired (flexible lift cables) or
have very low load currents (cables to fire detectors, data cables..).
DC cables for PV installations
power cords of the electrical apparatus and the internal wiring of these
apparatus,
building automation systems, lighting controls, …..
1.1.4 Prodcom category or categories
The only category found in Prodcom, related to the scope of this study, is the category
with NACE code 27321380.
Table 1-2 ProdCom data
Prodcom NACE code Description
27321380 Other electric conductors, for a voltage <= 1000 V, not fitted with connectors
23
1.1.5 Categories according to IEC, EN- or ISO-standard(s)
Cables can be roughly divided into High voltage cables (> 1kVac) & Low voltage cables
(<1kVac). These are the topics of respectively Working Group 16 and Working Group
17 of IEC TC 20 (Electric Cables).
The following sections list IEC standards defining subcategories of cables according to
the field of application.
1.1.5.1 IEC 60228
IEC 60228: “Conductors of insulated cables” defines 4 classes for conductors:
- Class 1: solid conductor
- Class 2: stranded conductors
- Class 5: flexible conductors
- Class 6: flexible conductors which are more flexible than class 5
Whereas Class 1 and 2 conductors are intended for use in cables for fixed installation.
Class 5 and 6 are intended for use in flexible cables and cords but may also be used for
fixed installation.
Functional difference is the minimum bending radius which is expressed in x times the
outer diameter of the cable.
1.1.5.2 IEC 60227-1
The following classes and types are defined in IEC 60227-1: “Polyvinyl chloride cables
of rated voltage up to and including 450/750V – general requirements”:
0. Non-sheathed cables for fixed wiring.
01. Single-core non-sheathed cable with rigid conductor for general purposes
(60227 IEC 01).
02. Single-core non-sheathed cable with flexible conductor for general purposes
(60227 IEC 02).
05. Single-core non-sheathed cable with solid conductor for internal wiring for a
conductor temperature of 70 °C (60227 IEC 05).
06. Single-core non-sheathed cable with flexible conductor for internal wiring for a
conductor temperature of 70 °C (60227 IEC 06).
07. Single-core non-sheathed cable with solid conductor for internal wiring for a
conductor temperature of 90 °C (60227 IEC 07).
08. Single-core non-sheathed cable with flexible conductor for internal wiring for a
conductor temperature of 90 °C (60227 IEC 08).
1. Sheathed cables for fixed wiring.
10. Light polyvinyl chloride sheathed cable (60227 IEC 10).
1.1.5.3 IEC 60245-1
IEC 60245-1: “Rubber insulated cables – Rated voltages up to and including 450/750
V – Part 1: General requirements” defines the following classes and types:
0 Non-sheathed cables for fixed wiring
03 Heat-resistant silicone insulated cable for a conductor temperature of maximum
List of Acronyms
24
180 °C (60245 IEC 03).
04 Heat-resistant ethylene-vinyl acetate rubber insulated, single-core non-
sheathed 750 V cable with rigid conductor for a maximum conductor
temperature of 110 °C (60245 IEC 04).
05 Heat-resistant ethylene-vinyl acetate rubber insulated, single-core non-
sheathed 750 V cable with flexible conductor for a maximum conductor
temperature of 110 °C (60245 IEC 05).
06 Heat-resistant ethylene-vinyl acetate rubber or other equivalent synthetic
elastomer insulated, single-core non-sheathed 500 V cable with rigid conductor
for a maximum conductor temperature of 110 °C (60245 IEC 06).
07 Heat-resistant ethylene-vinyl acetate rubber or other equivalent synthetic
elastomer insulated, single-core non-sheathed 500 V cable with flexible
conductor for a maximum conductor temperature of 110 °C (60245 IEC 07).
1.1.6 Other product-specific categories
In general cables can be categorised according to their field of application or the
composition of the cable.
Categories according to the field of application (typically found in cable catalogue):
Energy (or power) cables: Cables for transmission & distribution of electrical
energy
o LV, MV and HV (AC/DC) cables
o Underground / overhead cables
Industrial cables
o LV,MV,(HV) cables
o Power, control, instrumentation.. cable
Building wire cable
o Cables for fixed wiring (e.g. Class 1&2– EN60228)
o Other (flexible) cables (e.g. Class 5&6 – EN 60228)
Special purpose cables (automotive, railway, renewables, military…)
Communication cables (data, telephone..)
Categories according to the composition of the cable:
Conductor material: Copper or Aluminium
Insulation and sheath material: bare or insulated conductors/cables. Insulation
and sheath material depends on:
o The rated voltage level: LV, MV, HV
o Mechanical requirements: bending radius, elongation, tensile strength,
abrasion, max diameter, ..
o Chemical requirements: resistance to chemical products (oil, fuels,
acids,..) and resistance to fire/heat, halogen free
A further categorisation can be made, based on:
Nominal Cross sectional area of the conductors (expressed in mm²): value that
identifies a particular size of a conductor but is not subject to direct
measurement (IEC 60228)
The construction of the conductor: Solid, stranded, flexible
The amount of conductors in the cable: single core or multicore
TBC
25
1.1.7 Proposal for primary product performance parameter or ‘functional
unit’
Knowing the functional product used in this study we now further explain what is called
the “functional unit” for power cables.
In standard 14040 on life cycle assessment (LCA) the functional unit is defined as “the
quantified performance of a product system for use as a reference unit in life cycle
assessment study”. The primary purpose of the functional unit is to provide a
calculation reference to which environmental impacts (such as energy use), costs, etc.
can be related and to allow for comparison between functionally equal electrical power
distribution cables and/or circuits. Further product segmentations will be introduced in
this study in order to allow appropriate equal comparison.
The proposed primary functional performance parameter is “current-carrying
capacity”.
The “current-carrying capacity” of a cable or (insulated) conductor is defined as the
maximum value of electric current which can be carried continuously by a conductor (a
cable), under specified conditions without its steady-state temperature exceeding a
specified value (see IEV 826-11-13). The current-carrying capacity is expressed in
Amperes [A].
The current-carrying capacity of a cable depends on:
Conductor material: Cu or Al or alloys;
Nominal cross sectional area of the conductor (expressed in mm²);
Insulation material: maximum operating temperature (e.g. PVC=70°C, XLPE=
90°C);
Ambient temperature at the place where the cable is installed;
Method of installation: The installation method has an impact on the heat
transfer from the conductor to the environment.
Note: in some North-American countries the word “ampacity” is used to express the
current-carrying capacity.
1.1.8 Secondary product performance parameters
These parameters can be divided in two subcategories:
secondary product performance parameter related to the construction of the
cable;
secondary product performance parameter related to the use of the cable.
1.1.8.1 Secondary product performance parameters related to the
construction of the cable
The secondary product performance parameters related to the construction of the cable
are:
Nominal Cross-Sectional Area (CSA): a value that identifies a particular size
of conductor but is not subject to direct measurement, expressed in mm² (IEC
60228). The csa of the conductor is standardized: e.g. 0.5 mm², 0.75mm², 1
mm², 1.5 mm², 2.5 mm² …. In the USA & Canada conductor sizes according to
AWG (American Wire Gauge) – see standard: ASTM B258 - 02(2008)
List of Acronyms
26
The cross-sectional area of conductors shall be determined for both normal
operating conditions and for fault conditions according to (IEC 60364-1):
their admissible maximum temperature;
the admissible voltage drop;
the electromechanical stress likely to occur due to earth fault and short
circuit currents;
other mechanical stress to which the conductor can be subjected;
the maximum impedance with respect to the functioning of the protection
against fault currents;
the method of installation.
Note: The items listed above concern primarily the safety of electrical
installations. Cross-sectional areas greater than those for safety may be
desirable for economic operation.
DC resistance (R20): Direct current resistance of the conductor(s) at 20°C
expressed in Ohm/km (IEC 60228 – Annex A). The DC resistance of solid
conductors (Class 1) are lower than these of flexible conductors (Class 5,6), e.g.
For a Class 1, 1 mm² Cu wire R20= 18.1 Ohm/km; for a class 5, 1 mm² Cu wire
R20= 19.5 Ohm/km;
Rated voltage Uo/U: The rated voltage of a cable is the reference voltage for
which the cable is designed and which serves to define electrical tests (IEC
60227-1). The rated voltage is expressed by the combination of two values Uo/U
expressed in volts:
U0 is the r.m.s value between any insulated conductor and “earth” whereas
U is the r.m.s value between any two-phase conductor of a multicore cable
or of a system of single-core cables.
Insulation material: synthetic insulation materials can be roughly divided into:
Thermoplastics (PVC, PE, PP,..);
Thermosettings (Neoprene, Silicone Rubber…);
Elastomers (XLPE, EPR,…).
The selection criteria of the insulation material depends on the electrical (rated
voltage, ..) and physical (temperature range, flexibility, flammability, chemical
resistance…) requirements of the application.
Conductor material (Cu, Al): Copper and aluminium are the most commonly
used metals as conductors. The compositions of copper and aluminium wire for
the manufacturing of electrical conductors are specified in respectively
EN13601/13602 and EN1715.
Number of cores in the cable: In general a distinction is made between single
core and multi-core cables. A single core cable consists of only one conductor
covered by an insulation material (1 or 2 layers). A multi-core cable consists of
2, 3, 4, 5 or more cores, each individually insulated and globally covered by a
sheath. In general conductors in a cable have the same CSA, but there are also
cables with other combinations. For instance for balanced three-phase systems
the neutral can have a smaller CSA than the phase conductors, sometimes
indicated as 3.5 (3 conductors with the same size, 1 conductor with a smaller
CSA) or 4.5 (4 conductors with the same size, 1 conductor with a smaller CSA).
Also the protective earth conductor can have a smaller CSA.
27
The construction of the conductor: Solid, stranded, flexible. Solid wire, also
called solid-core or single-strand wire, consists of one piece of metal wire.
Stranded wire is composed of smaller gauge wire bundled or wrapped together
to form a larger conductor. The type of construction mainly has an effect on the
flexibility/bending radius, but it has also an effect on the AC resistance of the
cable.
1.1.8.2 Secondary product performance parameter related to the use of the
cable
Secondary product performance parameters related to the use of the cable in an
electrical installation system are the following:
At the level of the electrical installation system:
Supply parameters & topology of the grid:
o Nominal voltage (U and/or Uo)
o Maximum and minimum fault currents to earth and between live
conductors
o Maximum supply loop impedance to earth (Z41), given as a minimum
fault current
o AC Grid system (TT, TN, IT) / DC (marginal, see BAT)
o Single phase or three phase electrical installation. A single phase
installation consists of single phase circuits. A three phase installation can
consist of any combination of single phase and three phase circuits;
Design of the electrical distribution system in the building (see FprHD 60364-8-
1)
o Main and/or sub distribution board (levels). Small installations have just
one level, the main distribution board feeding the circuits. Larger
installations in general have two levels, the main distribution board
serving secondary distribution boards. Exceptionally, very large
installations or installations with special design requirements may have a
third level.
o Installation cable length: the total length of all fixed wired power cables
used in the total electrical installation of a building;
o Method of installation: in cable trunk, inside the wall, in open air,
grouped, indoor/outdoor. Reference installation methods and their
corresponding correction factors are defined in IEC 60364-5-52;
External influences (see IEC 60364-5-51), such as:
o Environmental conditions:
Ambient temperature: A correction factor for ambient
temperatures other than 30°C has to be applied to the current-
carrying capacities for cables in the air (IEC 60364-5-52). Higher
ambient temperatures have a negative effect on the current-
carrying capacity of the cable, e.g. a correction factor of 0.87 has
to applied for PVC cables installed in locations with a ambient
temperature of 40°C;
Presence of corrosive or polluting substances: the sheath material
of the cable must be resistant to the substances at which it is
exposed to;
o Utilisation of the building: The utilisation of the building has a significant
impact on the choice of the cables, especially on the fire behaviour of the
cables. Important building aspects related to this topic are:
List of Acronyms
28
Condition of evacuation in case of emergency
Nature of processed or stored material
o Construction of the building: cables must be conform to the performance
criteria of the Construction Product Directive / Construction Product
Regulation (see further on)
At the level of the circuit:
Voltage drop over the cable in a circuit (Volt): an electric current flowing
through a resistive material (conductor) creates a voltage drop over the material.
The voltage drop depends on the resistance of the conductor (Cu, Al), the
amount of current flowing through the conductor (depends on the electrical
load) and the length of the cable. The voltage drop can be calculated with the
following formula (IEC 60364-5-52):
(
)
Where
u= voltage drop in volts;
b= the coefficient equal to 1 for three-phase circuits and equal to 2 for
single-phase circuits;
ρ1= the resistivity of the conductor in normal service, taken equal to the
resistivity at the temperature in normal service, i.e. 1.25 times the
resistivity at 20°C, or 0.0225 Ωmm²/m for copper and 0.036 Ωmm²/m
for aluminium;
L= the straight length of the wiring systems in metres;
S= the cross-sectional area of conductors, in mm2;
cos φ= the power factor; in the absence of precise details, cos φ is taken
as equal to 0,8 ;
λ= the reactance per unit length of conductors, which is taken to be 0,08
mΩ/m in the absence of other details;
Ib is the design current (in amps);
Load current (Ampere): This is the design current of the electric circuit and is
determined by the electric load in normal operation connected to the circuit. The
load current can be calculated as follow:
for single phase systems
for three phase systems
Where P= active power of the load (Watt)
Uo= nominal voltage between line and neutral
U= nominal voltage between the lines
Cos φ = power factor of the load
Icircuit: is rated current for the circuit and is determined by the protective device
(safety fuses or circuit breakers) of the circuit;
29
Single phase or three phase circuit;
Circuit topology: radial, loop, line, tree circuit;
Load factor (LF) (IEV 691-10-02):
The ratio, expressed as a numerical value or as a percentage, of the
consumption within a specified period (year, month, day, etc.), to the
consumption that would result from continuous use of the maximum or other
specified demand occurring within the same period
Note 1 – This term should not be used without specifying the demand and the
period to which it relates.
Note 2 – The load factor for a given demand is also equal to the ratio of the
utilization time to the time in hours within the same period.
As a consequence the load factor is an important parameter for calculating the
energy losses in the cable;
Load form factor (Kf) (derived from IEV 103-06-14): the ratio of the root mean
squared (r.m.s) Power to the average Power (=Prms/Pavg);
o The r.m.s or root mean square value is the value of the equivalent direct
(non varying) voltage, current, power which would provide the same
energy to a circuit as the sine wave. That is, if an AC sine wave has a
r.m.s value of 240 volts, it will provide the same energy to a circuit as a
DC supply of 240 volts. The r.m.s value can be calculated as follow:
√
∫
For a sine wave (eg. Grid voltage, power): y with amplitude “a”
and frequency “f”, the r.m.s value is . or
o The avg or average value is normally taken to mean the average value of
only half a cycle of the wave. If the average of the full cycle was taken it
would of course be zero, as in a sine wave symmetrical about zero, there
are equal excursions above and below the zero line.
o
For a sine wave (eg. Grid voltage, power): y=a sin(2πft) with amplitude “a”
and frequency “f” , the avg value is
List of Acronyms
30
Figure 1-6: Peak-, r.m.s-, avg value of a sine wave
The equivalent operating time at maximum loss, in h/year; (IEC 60287-3-2) : is
the number of hours per year that the maximum current Imax would need to
flow in order to produce the same total yearly energy losses as the actual,
variable, load current;
∫
where
t is the time, in hours;
Ib(t) the load current in function of time, in A;
Imax is the maximum load on the cable during the first year, in A;
The energy losses according IEC 60287-3-2 are:
where
Imax is the maximum load on the cable during the first year, in A;
RL is cable resistance per unit length;
L is the cable length, in m;
NP is the number of phase conductors per circuit (=segment in this
context);
NC is the number of circuits carrying the same type and value of
load;
T is the equivalent operating time, in h/year.
Be aware that the formula used in IEC 60287-3-2 is only used to calculate the
cable losses for cable segments. Compared to circuits the load is situated at the
end of the cable, having an equal load (current) over the total length of the
cable.
31
Cos φ (or power factor; IEC 60364-5-52) of the load: is defined as the ratio of
active power (P – kWatt) to the apparent power (S – kVA).
Figure 1-7: Relationship between active-, reactive- and apparent power
Where:
Active Power (P) (IEV 141-03-11): For a three-phase line under symmetric and
sinusoidal conditions, the active power is , where U is the r.m.s value
of any line-to-line voltage, I is the r.m.s value of any line current and φ is the
displacement angle between any line-to-neutral voltage and the corresponding line
current.
Apparent Power (S) (IEV 131-11-41): product of the r.m.s voltage U between the
terminals of a two-terminal element or two-terminal circuit and the r.m.s electric
current I in the element or circuit expressed in VoltAmpere, VA. For a three-
phase system, the apparent power is .
Short-circuit intensity: Short-circuits causes large currents in the conductors
which lead to thermal stresses in these conductors. Therefore the breaking time
for a short-circuit may not be greater than the time taken for the temperature of
the conductors to reach maximum permissible value. The maximum thermal
stresses of a cable depends on:
o Insulation material (PVC, XLPE,..)
o Conductor material (Cu, Al)
o Cross sectional area of the conductors
Harmonic currents (will be defined later in task 3).
Kd distribution factor (defined for this study): distribution of the load over the
cable of a circuit. A circuit can have several connection terminals along the
circuit with different loads attached to it. As a result the current passing along
the circuit reduces towards the end. This distribution factor compensates this
effect by reducing the cable length to an equivalent cable length at peak load.
Note this is probably only relevant for small loads, as in general larger loads are
fed by dedicated circuits serving one single load;
P - Active Power (kWatt)
Q -
Reactive P
ow
er
(k
VAr)
φ
List of Acronyms
32
Rated Diversity Factor (IEC 61439): the rated current of the circuits will be
equal to or higher than the design current (or assumed loading current). The
Rated Diversity Factor recognizes that multiple loads are in practice not fully
loaded simultaneously or are intermittently loaded.
Amount of junction boxes per circuit;
Number of nodes per circuit;
Circuit levels 1 and 2 (defined for this study) (see also Figure 1-5);
o Circuit level 1 cables are cables that feed the secondary distribution
boards from the main distribution board;
o Circuit level 2 cables are cables that are connected to the end loads.
Number of load per circuit;
Skin effect, skin depth8: skin effect is the tendency of an alternating electric
current (AC) to become distributed within a conductor such that the current
density is largest near the surface of the conductor. It decreases with greater
depths in the conductor. The electric current flows mainly at the "skin" of the
conductor, between the outer surface and a level called the skin depth δ. The
skin effect causes the effective resistance of the conductor to increase at higher
frequencies where the skin depth is smaller, thus reducing the effective cross-
section of the conductor.
Lifetime of the cable: the lifetime of a cable depends mainly on the nominal load
current and the environmental conditions (temperature, presence of corrosive or
polluting substances ...) in which the cable is installed. Short circuits have an
negative impact on the lifetime, because of the high conductor temperatures
caused by the short circuit currents.
1.1.9 First screening
Objective:
The first product screening is a preliminary analysis that sets out the recommended
scope for the subsequent Tasks. As the full study investigates the feasibility and
appropriateness of Ecodesign and/or Energy Labelling measures, the first product
screening entails an initial assessment of the eligibility and appropriateness of the
product group envisaged.
Important note: (Note: these values are updated in later chapters)
1.1.9.1 Envisaged product application categories
When the classification is performed according the main application of the circuit, 12
categories are defined (see Table 1-3).
8 http://en.wikipedia.org/wiki/Skin_effect
33
Table 1-3: Application categories
At circuit level 1 there is one type of circuit per sector, e. g. Figure 1-5. The main
function of a level 1 circuit is to feed the secondary distribution boards. Standalone
single family houses in the residential sector generally have one circuit level, but for
instance apartment buildings have two circuit levels (secondary distribution board per
dwelling).
At circuit level 2 we differentiate between lighting circuits, socket-outlet circuits and
dedicated circuits (see for example in Figure 1-4 and Figure 1-5). Each circuit type has
one or more typical topologies. For instance lighting circuits can be designed as single
line circuit (no branches), as a tree by means of junction boxes (with one branch per
node), or as a star. Socket-outlet circuits in general are single line circuits or looped
circuits. Dedicated circuits serve mostly just one load. For instance a motor or pump
with a dedicated circuit breaker in the distribution board and a cable between circuit
breaker and load. The load is thus located at the end of the dedicated circuit. For
lighting and socket-outlet circuits the load is distributed along the circuit.
Acronyms for circuit identification based upon the above mentioned application
categories in Table 1-3:
RESidential Level1 circuit: RESL1
SERvices Level1 circuit: SERL1
INDustry Level1 circuit: INDL1
RESidential Level2 Lighting circuit: RESL2L
SERvices Level2 Lighting circuit: SERL2L
INDustry Level2 Lighting circuit: INDL2L
RESidential Level2 Socket-outlet circuit: RESL2S
SERvices Level2 Socket-outlet circuit: SERL2S
INDustry Level2 Socket-outlet circuit: INDL2S
RESidential Level2 Dedicated circuit: RESL2D
SERvices Level2 Dedicated circuit: SERL2D
INDustry Level2 Dedicated circuit: INDL2D
1.1.9.2 Parameters determining power loss in cables
This section elaborates the physical parameters of a power cable related to losses in the
cable.
As stated in the previous section the power losses are proportional to the cable
resistance (R). The resistance of a cable in circuit at a temperature t can be calculated
by the formula: R= ρt.l/A (Ohm). This means the losses in a circuit can be diminished
by:
reducing the specific electrical resistance (ρ) of the conductor material;
increasing the cross sectional area (A) of the cable;
reducing the total length (l) of cable for a circuit.
List of Acronyms
34
In annex 1-B a closer look is taken at these physical parameters and at how
manipulation of these parameters can contribute to smaller power losses in power
cables.
1.1.9.3 Preliminary analysis according to working plan
The preliminary analysis in this section is based upon data from the “Modified Cable
Sizing Strategies, Potential Savings” study9 – Egemin Consulting for European Copper
Institute – May 2011. This study is also referred to in the ErP Directive Working plan
2012-201410. It focuses on the use of electrical conductors with cross-sections beyond
the minimum safety prescriptions, which helps to achieve energy savings and cost-
effectiveness.
1.1.9.3.1 Market and stock data for the first screening
Electrical installations in buildings were modelled by their content of conductive
material. The analysis was carried out considering the equivalent content of copper of
the electrical installation (largely dominated by the electrical conductor).
Buildings can be split into three main categories:
Residential;
Non-residential;
Industry;
Services.
This classification (residential, industry, services) corresponds with available statistical
and forecast data on electricity consumption, which allows making estimates of
potential energy savings.
Annual sales of wiring, expressed as kilotons equivalent copper, are estimated to be
some 760 kTon in 2010, and are expected to increase to 924 kTon in 2030 (see Table
1-4).
Table 1-4: Sales of power cables (kTon Copper)11
Annual Sales (kTons eq.
Copper) 2000 2005 2010 2015 2020 2025 2030
Industry 226 245 241 253 266 279 293
Services 202 219 216 227 238 250 263
Residential 284 308 303 318 334 351 368
Total 712 772 760 798 838 880 924
The total amount of copper installed in buildings ('stock') is estimated to be some
18788 kTon in 2010, expected to increase to 21583 kTon in 2030 (see Table 1-5).
9 http://www.leonardo-energy.org/white-paper/economic-cable-sizing-and-potential-savings 10 http://ec.europa.eu/enterprise/policies/sustainable-business/ecodesign/product-groups/
11 http://ec.europa.eu/enterprise/policies/sustainable-business/ecodesign/product-groups/
35
Table 1-5: Stock of power cables (kTon of Copper)11
Stock (kTons eq. Copper) 2000 2005 2010 2015 2020 2025 2030
Industry 5991 6102 6538 6951 7395 7453 7511
Services 4338 4419 4734 5033 5355 5397 5439
Residential 6886 7014 7515 7989 8500 8567 8633
Total 17215 17536 18788 19974 21250 21417 21583
The gap between the stock increase and the cumulative 5 years sales is due to
refurbishment, maintenance and extension of existing installations as well as
dismantling of old buildings.
Information sources were:
Residential and non-residential new construction and refurbishment activity
(Euroconstruct database)
Demographic statistics, households statistics and projections (Eurostat,
European Union portal, European Environmental Agency)
Copper wire and cable consumption (European Copper Institute)
Assumptions were:
30 kg of equivalent copper per electrical installation of a household.
Stock in non-residential buildings = 1.5 times the stock in residential buildings
(based on copper wire and cable consumption statistics).
1.1.9.3.2 Cable loading data for first screening
Losses in electrical cables are related to the loading (see 1.1.9.2). This electric loss is
therefore directly related to the overall electricity consumption in the buildings
concerned.
Hence, the Reference scenario for the calculations is defined by the projections made
by the European Commission 12 regarding electricity consumption in buildings and
industrial indoor sites. Note that probably part of the industry electricity consumption
(see Table 1-6) can strictly not be seen as cables inside buildings, they could be located
outdoor but due to a lack of data this is neglected at this stage.
Table 1-6: Final affected energy demand, related to power cables13
FINAL ENERGY DEMAND -
Reference Scenario Unit 2010 2015 2020 2025 2030
Industry TWh 1073 1152 1207 1279 1329
Services TWh 775 832 872 924 960
Residential TWh 950 1021 1069 1133 1177
Total Electricity TWh 2798 3005 3148 3336 3466
Total Electricity PJelec 10074 10818 11334 12011 12478
Total energy PJ
prim 25182 27045 28332 30024 31194
1.1.9.3.3 Estimated losses in cables in buildings
12 http://ec.europa.eu/energy/observatory/trends_2030/doc/trends_to_2030_update_2009.pdf
List of Acronyms
36
In the Modified Cable Sizing Strategies, Potential Savings” study – Egemin Consulting
for European Copper Institute – May 2011, referred to in the ErP Directive Working plan
2012-201413, four electrical systems were defined modelling and representing a small
office, a large office, a small logistics centre and a large industrial plant.
The calculated averaged energy loss in power cables for the sectors defined in this
study was 2.04%.
Some stakeholders made remarks to the above mentioned study14. In the next sections
we will re-analyse the assumptions made in the Egemin study.
1.1.9.4 Review of losses
In the following sections the losses in the circuits, classified according the product
application categories in 1.1.9.1, have been calculated. Analogue to the study
elaborated in 1.1.9.3.3, a residential and non-residential model have been worked out
based upon empirical findings. Beware that every individual installation and loading can
vary a lot compared to those assumptions.
The parameters used in the models are explained in chapter 3 of this report. The length
of the circuits in the models is based upon the answers on the questionnaire for
installers15. The acronyms used for the circuit identification are listed in 1.1.9.1.
The loss ratio used in the model is defined as:
Two loss ratios are used:
Loss ratio on Imax: this is according formula on energy losses in power cables
explained in chapter 3;
Loss ratio on Iavg: this is according the P= R.Iavg² formula. Formula to calculate
the average value see xxxxx
1.1.9.4.1 Estimated residential cable losses
Average annual household consumption in Europe is 3500kWh, resulting in an average
power usage of 400 W and an average current of 1.74 A at 230 V. According to MEErP16
the average floor area for existing residential dwellings (year 2010) is 90 m2 and 110
m2for new residential dwellings.
The assumed residential model consists of one level 1 circuit (RESL1), 2 lighting
(RESL2L), 2 socket-outlet (RESL2S) and 2 dedicated circuits (RESL2D). The length of
13 http://ec.europa.eu/enterprise/policies/sustainable-business/ecodesign/product-groups/ 14 Ivar GRANHEIM [email protected], by mail 20/09/2013,
The report motivating the inclusion of power cables in the Working Plan is
missing key information to evaluate the effective potential saving of power
cables, and assumptions are not robust. A more complete technical study is
needed. 15 http://www.erp4cables.net/node/6, this questionnaire was sent to installers on the 30th of
September, 2013 in the context of this study. 16 MEErP 2011 Methodology Part 2 , chapter 6.5, edition 28 November 2011
37
the circuits in the model is about 30 m for the cat 1 circuit and 17 to 20 m for the other
circuits. The total amount of conductor material (copper) used in this model is 25
kg/100m2. It is assumed that the phases are in balance (no current through neutral
conductor in case of 3-phase circuit).
Table 1-7: Residential model: parameters and calculated losses (Note: these values are
updated in later chapters)
Summary Circuits Installation
RESL1 RESL2L RESL2S RESL2D RESL2D
Total circuit length (m) 30 34 40 17 17
CSA (mm²) 10 1.5 2.5 2.5 6
Loaded cores 3 2 2 2 2
Kd (distribution factor) 1.00 0.50 0.50 1.00 1.00
LF (load factor = Pavg/S =
Iavg/Imax) 0.03 0.01 0.02 0.01 0.01
Kf (load form factor) 1.08 1.29 2.83 6.48 4.90
PF (power factor) 0.90 0.90 0.90 0.90 0.90
loss ratio on Imax 0.15% 0.02% 0.09% 0.21% 0.06% 0.24%
loss ratio on Iavg 0.12% 0.02% 0.03% 0.03% 0.01% 0.15%
The loads used for the RESL2D circuits are a washing machine and an induction cooker.
Most of the losses are in the level 1 circuit and in the dedicated circuits. Due to the low
load factor the losses are rather small (see Table 1-7).
1.1.9.4.2 Estimated service sector cable losses
An average office17 of 400m² is used with about 33 employees, and an annual energy
usage of 166666 kWh. The model consists of one level 1 circuit (SERL1), lighting
(SERL2L), socket-outlet (SERL2S) and dedicated (SERL2D) circuits. The length of the
circuits in this model is about 30 to 35 m according the results of the enquiry18. The
total amount of conductor material (copper) used in this model is about 96 kg/100m2.
It is assumed that the phases are in balance (no current through neutral conductor in
case of 3-phase circuit).
17 http://www.entranze.eu/, http://www.leonardo-energy.org/sites/leonardo-energy/files/documents-and-links/Scope%20for%20energy%20and%20CO2%20savings%20in%20EU%20through%20BA_2013-09.pdf The scope for energy and CO2 savings in the EU through the use of building automation technology. 18 http://www.erp4cables.net/node/6, this questionnaire was sent to installers on the 30th of September, 2013 in the context of this study.
List of Acronyms
38
Table 1-8: Services model: parameters and calculated losses(Note: these values are
updated in later chapters)
Summary Circuits Installation
SERL1 SERL2L SERL2S SERL2D SERL2D
Total circuit length (m) 50 258 155 57 57
CSA (mm²) 95 1.5 2.5 25 35
Loaded cores 3 2 2 3 3
Kd (distribution factor) 1.00 0.50 0.50 1.00 1.00
LF (load factor = Pavg/S =
Iavg/Imax) 0.36 0.12 0.25 0.12 0.10
Kf (load form factor) 1.08 1.06 1.23 1.06 1.43
PF (power factor) 0.90 0.90 0.90 0.90 0.90
loss ratio on Imax 1.67% 0.38% 0.68% 0.63% 0.61% 2.26%
loss ratio on Iavg 1.39% 0.32% 0.50% 0.53% 0.38% 1.83%
The electrical losses in this electrical installation defined by the parameters listed in
Table 1-8 are about 2.26% of the total transported electricity consumed by the loads.
1.1.9.4.3 Estimated industry sector cable losses
In the industry sector and in most cases in the services sector the electrical installation
network is designed and worked out by means of an integrated calculation software tool.
The IEC recommends a maximum voltage drop at the connection terminals of the
electric load (the end point of the circuit) of 3% for lighting circuits and 5 %for other
circuits, when supplied from public voltage distribution (see Table 1-16). The
recommended limits for installations when supplied from private LV power supplies are
even higher (6% for lighting circuits, 8% for other circuits). Consider that this is a
recommendation (presented in an informative annex of standard IEC 60634-5-52) and
only provides some guidance to designers. In some countries the IEC recommendations
are in fact legal requirements, while in other countries similar requirements can be
included in local legislation.
Based upon the following assumptions:
designers use the above mentioned recommendation to design the electrical
installation;
in general the loads in the industry have a rather high load factor;
most of the energy is transported via dedicated circuits with a high distribution
factor (limited number of terminals/loads per dedicated circuit);
one can conclude that:
the losses in cables in the electrical installation in the industry sector will be
between 1% and 8%.
A loss ratio of 2% mentioned in 1.1.9.3.3 is plausible. The following tasks will continue
to estimate this loss ratio.
1.1.9.4.4 Summary of estimated cable losses
Looking at the results in the previous sections the calculated losses are in line with the
average result of about 2% losses for electrical installations in the services and
39
industry sector, concluded in the EGEMIN study 19 . The calculated losses in the
residential sector, however, are much lower (less than 0.3% compared to 2%). This
can be explained by the following reasons:
The circuits in the residential buildings are in general much shorter than the
circuits in the services or industry sector. This is also confirmed by the results of
the questionnaire to the installers. Only in multi-dwellings the level 1 circuits can
be considerably long and can contribute significantly to the losses in the
electrical installation in residential dwellings.
The load profile (load factor and load form factor) in the residential and non-
residential sector differ a lot. In the residential sector the load factor is rather
low and the load form factor can be rather high. In the non-residential sector
the load profile is more evenly, but with a higher average load per circuit. Again,
in general the level 1 circuit in the residential sector also has a higher average
load.
Most of the installers (75%) that responded to the enquiry20 estimated that the losses
in the electrical installation vary between 1% and 3%. The others (25%) estimated a
loss of less than 1%.
1.1.9.5 Improvement potential by increasing the cross sectional area of the
cable
The Egemin study 21 estimated that cable losses could be reduced from 2% up to
0.75% (see Table 1-9) when applying the economic strategy. The study formulated
four alternative strategies based on increased conductor cross-sections:
One size up (S+1) strategy: selection of 1 standard calibre size up from the
base line;
Two sizes up (S+2) strategy: selection of 2 standard calibre sizes up from the
base line;
Economic optimum strategy: a cost minimisation algorithm is run balancing the
cost represented by the energy losses over a 10 year investment horizon and
the cost for initial purchase and installation of the cables;
Energy loss minimisation (carbon footprint minimisation) strategy: a
minimisation algorithm is run balancing the CO2 equivalent of the energy losses
over a 20 year lifetime horizon and the CO2 equivalent of copper production for
the cables copper weight.
Table 1-9: Impact on energy losses and copper usage (averaged over all models)21
Strategy Energy loss Loss reduction Cu weight Additional Cu
Base 2.04% 0.00% 100.0% 0.0%
S+1 1.42% 0.62% 141.6% 41.6%
S+2 1.02% 1.02% 197.7% 97.7%
Economic 0.75% 1.30% 274.2% 174.2%
Carbon 0.29% 1.76% 907.3% 807.3%
19 http://ec.europa.eu/enterprise/policies/sustainable-business/ecodesign/product-groups/ 20 http://www.erp4cables.net/node/6, this questionnaire sent to installers on the 30th of September, 2013 in the context of this study. 21 “Modified Cable Sizing Strategies, Potential Savings” study,Egemin Consulting for European Copper Institute, May 2011)
List of Acronyms
40
The averaged energy loss in power cables in this study was estimated at 2.04 % and
the losses can be reduced to 0.75% (loss reduction of 1.3%) applying the economic
strategy to the design of the electrical installation (see Table 1-9).
The potential savings are calculated on the basis of the building annual renewal rate22,
as indicated in the table below. The older installations maintain the conventional losses
pattern.
Table 1-10: Improvement scenario power cables23
Potential savings
(starting measures in
2013)
Unit 2010 2015 2020 2025 2030
annual rate (refurbishment) 3%
Stock of buildings - old
standard installations 100% 100% 85% 70% 55%
Stock of buildings - new
standard installations 0% 0% 15% 30% 45%
Improvement scenario -
final energy consumption PJprim/year 25182 27045 28277 29907 31012
Savings PJprim/year 0 0 55 117 182
Total electricity savings TWh/year 0 0 6 13 20
182 PJ/year of primary energy savings are forecasted by 2030 if the 'improved product'
is applied in electrical installations in buildings as of 2015, which corresponds to 20
TWh/year of electric energy savings (see Table 1-10).
Review of the improvement potential
In Annex 1-B another approach is used to calculate the improvement potential of a S+x
scenario, independent of a specific model. For each CSA the improvement is calculated
based upon the physical parameters. Independent of the amount of cable or the CSA
used, one can conclude that a S+1 scenario will reduce losses with minimum 17% and
maximum 40% (see Table 1-11). The exact savings in between the minimum and
maximum are determined by the amount of cable per cross-sectional areas and the
cross-sectional areas of the installed cables.
22 The refurbishment rate has been set at 3% following the rationale applied for thermal insulation products. Stakeholder Eurocopper applied higher refurbishment rates, but these have
been amended to better reflect historic refurbishment rates 23 http://ec.europa.eu/enterprise/policies/sustainable-business/ecodesign/product-groups/
41
Table 1-11 S+x scenario overview based upon CSA ratio (Note: these values are
updated in later chapters)
CSA resistance reduction based upon CSA ratio (S+x)/S
mm² S+1 S+2 S+3 S+4 S+5
Minimum 17% 33% 48% 58% 67%
Maximum 40% 63% 76% 85% 91%
Average 27% 47% 61% 71% 78%
Average for CSA 1,5 till CSA 10 38% 61% 74% 83% 89%
Average for CSA 1,5 till CSA 25 36% 58% 72% 81% 86%
For instance when cables with a cross-area section of 1.5 mm² till 10 mm² are used in
an electrical installation, opting for a S+1 upsizing strategy would on average reduce
the power losses in the installed cables by 38% and by 61 % for the S+2 strategy, by
74% for the S+3 strategy and so on.
A reduction in losses from 2.04% to 0.75% (reduction of 1,3%) implies a resistance
reduction of 63%. A scenario consisting of a combination of S+2 and S+3 strategies
corresponds with such a resistance reduction.
1.1.9.6 Other improvement potential options
There are other options for lowering losses in electrical installations, e.g. reducing the
load per circuit with parallel cables. These options are briefly touched in Annex 1-B and
will be researched in detail in Task 4 of this report.
1.1.9.7 Conclusion from the first screening
Important note: the input data and outcomes of the first screening are used
with the sole purpose to narrow the scope, they will be reviewed in later tasks.
There is a significant environmental impact.
The losses in power cables, based upon an average loss ratio of 0.3 % in the residential
sector and 2% in the non-residential sector, result in an annual loss in power cables of
3.5 TWh (0.3 % of 1177 TWh) in the residential sector in 2030 and 45.8 TWh (2%
of 1329+960 TWh) in the non-residential sector in 2030, or a total of 49.3 TWh.
Even when the residential sector would be taken out of the equation, this would still
mean a loss of about 46 TWh/year in 2030.
There is significant potential for improvement.
The calculations above proof that a modified sizing strategy, S+2 will reduce the losses
by 33% to 63%. With a penetration of 45 % of buildings with an electrical installation
according the S+2 strategy in 2030, this would mean an overall reduction of losses in
power cables by 15% to 28%. This is equal to annual savings between 7.3 TWh and 14
TWh in 2030. The maximum estimated potential savings with S+2 are in between
0.5 TWh and 1 TWh in the residential sector and in between 6.8 TWh and 13.0
TWh in the non-residential sector per year. A S+1 strategy in this case (S+1
List of Acronyms
42
strategy not applied in the residential buildings sector and 45% penetration) would
result in annual savings between 3.5 TWh and 8.24 TWh in 2030. An overview can be
found in Table 1-12.
Table 1-12: Overview annual savings in 2030 (Note: these values are updated in later
chapters)
Unit Residential
sector Services sector
Industry sector Total
Total without
residential sector
Energy consumption
TWh/y 1177 960 1329 3466.00 2289
Loss ratio
% 0.3% 2.0% 2.0%
Losses
TWh/y 3,531 19.2 26.58 49.31 45.78
Improvement scenario penetration in 2030
% 45% 45% 45%
S+1 strategy
minimum savings 17% TWh/y 0.27 1.47 2.03 3.77 3.50
S+1 strategy maximum savings
40% TWh/y 0.64 3.46 4.78 8.88 8.24
S+2 strategy
minimum savings 33% TWh/y 0.52 2.85 3.95 7.32 6.80
S+2 strategy maximum savings
63% TWh/y 1.00 5.44 7.54 13.98 12.98
There is a significant trade and sales volume.
An annual sales volume of 924 kTon copper in EU for power cables in 2030 is equal to a
volume of 103820 m³ copper or an equivalent of 69213 km single core cable with a
conductor CSA of 1.5 mm² or 346 km single core cable with a conductor CSA of 300
mm². At a price of 5.3 Euro/kg cable 924 kTon results in 4897 million Euro annual sales.
PRODCOM statistics lists for the NACE code 27321380 “Other electric conductors, for a
voltage <= 1000 V, not fitted with connectors” in 2012 for the EU28 a production of
2128 kTon and a production value of 12300 million Euro.
Losses in the residential sector are low and also the potential for
environmental is low.
Losses in the residential sector are estimated at 3.351 TWh (Table 1-12) and also the
improvement potential (0.27-1 TWh). Also cable loading can vary strongly between
installation circuits. Non-residential it is also proposed not to focus in residential
installation because the improvement potential is low (<> 2 TWh).
Conclusion on eligibility and scope:
Power cables installed in in the service and industry sector meet the criteria for “eligible”
products imposed by article 15 of ecodesign directive 2009/125/EC.
Power cables installed in the residential sector do not meet the criteria for “eligible”
products imposed by article 15 of ecodesign directive 2009/125/EC.
Ecodesign requirements will apply to power cables when they are placed on the market.
When the cables are placed on the market, it is not known in which sector the power
cables will be used and therefore residential cables should be in the scope of Tasks 1, 2
and 7 (partly) but not for Tasks 3-6 on environmental improvement potential.
43
1.2 Measurements/test standards
1.2.1.1 Relevant standards
Different types of EN documents are available:
Standards (EN-xxxxx): The EN-50000 to -59999 covers CENELEC activities and
the EN-60000 to -69999 series refer to the CENELEC implementation of IEC
documents with or without changes.
Technical Reports (TR): A Technical Report is an informative document on the
technical content of standardization work. Only required in one of the three
official languages, a TR is approved by the Technical Board or by a Technical
Committee by simple majority. No lifetime limit applies.
Harmonization Documents (HD): Same characteristics as the EN except for the
fact that there is no obligation to publish an identical national standard at
national level (may be done in different documents/parts), taking into account
that the technical content of the HD must be transposed in an equal manner
everywhere.
The most relevant standards for this study are explained in the following paragraphs.
1.2.1.1.1 EN 13601:2002 Copper and copper alloys - Copper rod, bar and wire for
general electrical purposes
This European Standard specifies the composition, property requirements including
electrical properties, and tolerances on dimensions and form for copper rod, bar and
wire for general electrical purposes.
Cross-sections and size ranges are:
round, square and hexagonal rod with diameters or widths across-flats from 2
mm up to and including 80 mm;
rectangular bar with thicknesses from 2 mm up to and including 40 mm and
widths from 3 mm up to and including 200 mm;
round, square, hexagonal and rectangular wire with diameters or widths across-
flats from 2 mm up to and including 25 mm, as well as thicknesses from 0.5 mm
up to and including 12 mm with widths from 1 mm up to and including 200 mm.
The sampling procedures, the methods of test for verification of conformity to the
requirements of this standard and the delivery conditions are also specified.
Annex A of this standard describes a general grouping of copper into 4 types:
Tough pitch coppers (i.e. oxygen-containing coppers);
Oxygen-free coppers;
Deoxidized coppers;
Silver-bearing coppers.
The main grade of copper used for electrical applications such as building wire, motor
windings, cables and busbars is electrolytic tough pitch copper CW004A (Cu-ETP) which
is at least 99.90% pure and has an electrical conductivity of at least 100% IACS
minimum. Tough pitch copper contains a small percentage of oxygen (0.02 to 0.04%).
If the high conductivity copper is to be welded or brazed or used in a reducing
atmosphere, then the more expensive oxygen free high conductivity copper CW008A
(Cu-OF) may be used24.
24 See: http://www.copperinfo.co.uk/alloys/copper/
List of Acronyms
44
An important electrical parameter for this study is the electrical conductivity of the
copper wire, expressed in [MS/m] or Mega Siemens per meter. A derived unit is the
electrical resistivity, expressed in [µΩ/m]. The minimum electric conductivity values for
the different copper alloys are defined in Table 3 of the standard.
Notes:
Copper having an electrical conductivity of 58 MS/m at 20°C (which corresponds
to a volume resistivity of 0.01724 µΩ x m at 20°C) is defined as corresponding
to a conductivity of 100% IACS (International Annealed Copper Standard);
Cu-ETP(CW004A) corresponds to E-Cu58 (DIN), Cu-a1 (NF), C101 (BS), C11000
(ASTM)…
1.2.1.1.2 EN 13602:2002 Copper and copper alloys. Drawn, round copper wire for the
manufacture of electrical conductors
This European Standard specifies the composition, property requirements including
electrical properties, and dimensional tolerances for drawn round copper wire from 0.04
mm up to and including 5.0 mm for the manufacture of electrical conductors intended
for the production of bare and insulated cables and flexible cords.
This standard covers plain or tinned, single or multiline, annealed or hard drawn wire.
It does not include wire for enamelling (winding wire, magnet wire), for electronic
application and for contact wire for electric traction. The sampling procedures, the
methods of test for verification of conformity to the requirements of this standard and
the delivery conditions are also specified.
1.2.1.1.3 IEC 60502-1: Power cables with extruded insulation and their accessories for
rated voltages from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) - Part 1:
Cables for rated voltages of 1 kV (Um = 1,2 kV) and 3 kV (Um = 3,6 kV)
This standard specifies the construction, dimensions and test requirements of power
cables with extruded solid insulation for rated voltages of 1 kV (Um = 1,2 kV) and 3 kV
(Um = 3,6 kV) for fixed installations such as distribution networks or industrial
installations. This standard includes cables which exhibit properties of reduced flame
spread, low levels of smoke emission and halogen-free gas emission when exposed to
fire.
Cables for special installation and service conditions are not included, for example
cables for overhead networks, the mining industry, nuclear power plants (in and around
the containment area), submarine use or shipboard application
For this study only the cables with a rated voltage U0/U (Um) of 0.6/1 (1.2kV) are
considered. Whereas:
U0 is the rated voltage between conductor and earth or metallic screen for which
the cable is designed;
U is the rated voltage between conductors for which the cable is designed;
Um is the maximum value of the "highest system voltage'' for which the
equipment may be used (see IEC 60038).
The conductors in the scope of this standard shall be either of Class 1 or Class 2 of
plain or metal-coated annealed copper or of plain aluminium or aluminium alloy, or of
Class 5 of plain or metal-coated copper in accordance with IEC 60228.
45
The types of insulating compounds covered by this standard are listed in table xxx
Table 1-13: Insulating compounds
The oversheath material shall consist of a thermoplastic compound (PVC or
polyethylene or halogen free) or an elastomeric compound (polychloroprene,
chlorosulfonated polyethylene or similar polymers). Halogen free sheathing material
shall be used on cables which exhibit properties of reduced flame spread, low levels of
smoke emission and halogen free gas emission when exposed to fire.
1.2.1.1.4 EN 60228: Conductors of insulated cables
EN 60228 specifies standardized nominal cross-section areas from 0.5 mm2 to 2 000
mm2, numbers and diameters of wires and resistance values of conductors in electric
cables and flexible cords.
Conductors are divided into four classes
Class 1: solid conductors;
Class 2: stranded conductors;
Class 5: flexible conductors;
Class 6: flexible conductors which are more flexible than class 5.
The maximum DC resistance of conductor at 20°C is defined for each Class and each
nominal cross sectional area for circular annealed, plain and metal-coated copper
conductors and aluminium (alloy) conductors.
A table of temperature correction factors kt for conductor resistance to correct the
measured resistance at t °C to 20°C is also included.
The measurement of conductor resistance is explained in Annex A of the standard: The
measurement must be done on complete length of cable or on a sample of at least 1
meter in length. The conductor resistance at the reference temperature of 20°C is
calculated with the following formula:
Where
Kt= temperature correction factor;
R20= conductor resistance at 20°C, in Ω/km;
Rt= measured conductor resistance, in Ω;
L= length of the cable (sample), in m.
List of Acronyms
46
Remark:
The maximum resistance of the conductor (Ω/km) is the most important specification
related to the energy losses in the power cable. An accurate measurement method to
determine this resistance is therefore essential. Nevertheless some important
requirements are missing in the measurement method described in Annex A of IEC
60228, such as:
- The maximum allowed uncertainty of the measurement equipment (resistance-,
length- and temperature measurement equipment);
- The temperature conditions of the test room;
- The time needed for temperature stabilisation of the test sample.
The above mentioned requirements are defined in IEC 60468:” Method of measurement
of resistivity of metallic materials”, but this standard is only applicable to solid (non-
stranded=Class 1) metallic conductor and resistor material. The maximum allowed
over-all uncertainty for the routine measurement method for resistance per unit length
is + 0.4%. IEC 60228 doesn’t refer to this standard.
47
Table 1-14: Maximum resistance of class 1 solid conductors (IEC 60228:2004)
Nominal cross-sectional area
Circular, annealed copper conductors
Aluminium and aluminium alloy
conductors, circular or shaped Plain Metal coated
mm² Ω/km Ω/km Ω/km
0.5 36 36.7 -
0.75 24.5 24.8 -
1 18.1 18.2 -
1.5 12.1 12.2 -
2.5 7.41 7.56 -
4 4.61 4.7 -
6 3.08 3.11 -
10 1.83 1.84 3.08
16 1.15 1.16 1.91
25 0.727 - 1.2
35 0.524 - 0.868
50 0.387 - 0.641
70 0.268 - 0.443
95 0.193 - 0.32
120 0.153 - 0.253
150 0.124 - 0.206
185 0.101 - 0.164
240 0.0775 - 0.125
300 0.062 - 0.1
400 0.0465 - 0.0778
500 - - 0.0605
630 - - 0.0469
800 - - 0.0367
1000 - - 0.0291
1200 - - 0.0247
Note: Due to low resistance values for the higher nominal cross-section areas,
accurate resistance measuring equipment is needed specially in case of short cable
samples (1….5 m). E.g. A 10 mm² class 1 plain annealed copper conductor has a
resistance of 1.83 Ω/km, for a sample length of 1 meter this is 0.00183 Ω or 1.83 m Ω.
1.2.1.1.5 EN 50525-1:2011 Electric cables - Low voltage energy cables of rated
voltages up to and including 450/750 V (U0/U) - Part 1: General
requirements
The EN 50525 (series) standards supersede HD 21.1 S4:2002 and HD 22.1 S4:2002.
List of Acronyms
48
This European Standard gives the general requirements for rigid and flexible energy
cables of rated voltages U0/U up to and including 450/750 Vac, used in power
installations and with domestic and industrial appliances and equipment.
Important NOTE in this standard (Note 3): National regulations may prescribe
additional performance requirements for cables that are not given in the particular
requirements. For example for buildings with high levels of public access, additional fire
performance requirements may be applicable.
The test methods for checking conformity with the requirements are given in other
standards, e.g. EN 50395: Electric test methods and EN 50396: Non-electrical test
methods.
The particular types of cables are specified in EN 50525-2 (series) and EN 50525-3
(series). The individual parts within those two series are collectively referred to
hereafter as "the particular specifications". Only the sizes (conductor class, cross-
sectional area), number of cores, other constructional features and rated voltages given
in the particular specification apply to the individual cable type. The code designations
of these types of cables are in accordance with HD 361.
Notes: National standards conflicting with EN 50525-1 have to be withdrawn on 2014-
01-17
1.2.1.1.6 EN HD 21.1 S4: Cables of rated voltages up to and including 450/750V and
having thermoplastic insulation – Part1: General requirements - Superseded
by EN 50525-1:2011
This harmonized document applies to rigid and flexible cables with insulation and
sheath, if any, based on thermoplastic materials, of rated voltages Uo/U up to and
including 450/750V, used in power installations.
HD 21.1 S4 specifies the marking of the cable and extension leads, the core
identifications, general requirements for the construction of the cables (conductors and
insulation) and requirements for the electrical and non-electrical tests for the
thermoplastic insulation materials
Note: HD 21.1 S4 is related to IEC 60227-1:1993 “Polyvinyl chloride insulated cables of
rated voltages up to and including 450/750 – Part 1: General requirements”, but is not
directly equivalent.
(Remark: IEC 60227-1993 and the amendment 1 and 2 is replaced by IEC 60227-1:
2007.)
HD 21.1 S4 defines for instance other types of insulation materials in comparison to IEC
60227-1:2007. HD 21.1 S4 defines types TI 1, TI 2, TI 4, TI 5 and TI 6 for conductor
insulation material, whereas IEC 60227-1 defines Type PVC/C (fixed installation),
PVC/D (flexible cables) and PVC/E (heat resistance cables).
1.2.1.1.7 EN HD 22.1 S4 “Cables of rated voltages up to and including 450/750V and
having cross linked insulation – Part1: General requirements” - Superseded
by EN 50525-1:2011
Note: HD 22.1 S4 is related to IEC 60245-1:1994 “Rubber insulated cables: Rated
voltages up to and including 450/750V – Part 1: General requirements”, but is not
directly equivalent.
49
1.2.1.1.8 HD 60364-1:2008 Low-voltage electrical installations - Part 1: Fundamental
principles, assessment of general characteristics, definitions
Harmonized Document 60364-1 (IEC 60364-1) gives the rules for the design, erection,
and verification of electrical installations. The rules are intended to provide for the
safety of persons, livestock and property against dangers and damage which may arise
in the reasonable use of electrical installations and to provide for the proper functioning
of those installations.
IEC 60364-1 applies to the design, erection and verification of electrical installations
such as those of
a) residential premises;
b) commercial premises;
c) public premises;
d) industrial premises;
e) agricultural and horticultural premises;
f) prefabricated buildings;
g) caravans, caravan sites and similar sites;
h) construction sites, exhibitions, fairs and other installations for temporary
purposes;
i) marinas;
j) external lighting and similar installations;
k) medical locations;
l) mobile or transportable units;
m) photovoltaic systems;
n) low-voltage generating sets.
IEC 60364-1 covers
a) circuits supplied at nominal voltages up to and including 1 000 Vac or 1 500
V d.c.;
b) circuits, other than the internal wiring of apparatus, operating at voltages
exceeding 1 000 V and derived from an installation having a voltage not
exceeding 1 000 Vac, for example, discharge lighting, electrostatic
precipitators;
c) wiring systems and cables not specifically covered by the standards for
appliances;
d) all consumer installations external to buildings;
e) fixed wiring for information and communication technology, signalling,
control and the like (excluding internal wiring of apparatus);
f) the extension or alteration of the installation and also parts of the existing
installation affected by the extension or alteration.
The different types of system earthing are explained in paragraph 312.2 of the
standard. The system earthing configuration is expressed by a 2 letter combination.
The first letter gives the relationship of the power system to earth:
T= direct connection of one point to the earth
I= all live parts isolated from earth, or one point connected to earth through a
high impedance
The second letter gives the relationship of the exposed-conductive parts of the
installation to earth:
T= direct electrical connection of exposed-conductive-parts to earth,
independently of the earthing of any point of the power system
N= direct electrical connection of the exposed-conductive-parts to the earthed
point of the power system.
List of Acronyms
50
The following system earthing configurations are most common:
1. TN systems, with some additional configurations:
o TN-S (Separated, neutral conductor and earth conductor are separated);
o TN-C (Common: neutral conductor and earth conductor are common);
o TN-C-S (Common-Separated: in a first part of the installation the neutral
and earth conductor are common in a second part of the installation they
are separated. After separation they must remain separated!).
Figure 1-8: TN-S system with separate neutral conductor and protective conductor
throughout the system
51
2. TT systems
Figure 1-9: TT system with separate neutral conductor and protective conductor
throughout the installation
3. IT systems
List of Acronyms
52
Figure 1-10: IT system with all exposed-conductive-parts interconnected by a
protective conductor which is collectively earthed.
1.2.1.1.9 HD 60364-5-52:2011: Low-voltage electrical installations - Part 5-52:
Selection and erection of electrical equipment - Wiring systems
IEC 60364-5-52:2009 contains requirements for:
Selection and erection of wiring systems in relation to external influences, such
as:
o Ambient temperature (AA);
o Presence of water (AD) or high humidity (AB);
o Presence of solid foreign bodies (AE);
o …
Determination of the current-carrying capacities which depends on:
o Maximum operating temperature of the insulation material (PVC: 70°C,
XLPE: 90°C..);
o The ambient temperature (Reference temperature is 30°C, the current-
carrying capacity decreases with increasing temperatures);
o The method of installation (examples of methods of installation are
defined in the Annex of the standard);
o The amount of single core or multi core cables grouped (in e.g. a cable
tray).
This standard also defines the minimum cross-sectional area of conductors (see Table
1-15)
53
Table 1-15: HD 60364-5-52:2011 minimum cross-sectional area
The minimum cross-sectional area for conductors used in fixed installations is 1.5 mm²
for copper and 10 mm² (!) for aluminium, as mentioned in Table 1-15. In the UK
1.0mm² copper cable is allowed for fixed installations utilizing cables and insulated
conductors for power and lighting circuits (see Note 5).
Remark: In IEC 60228 there are no specifications defined for Aluminium conductors
smaller than 10mm².
Special attention is needed for dimensioning the cross-sectional area of the neutral
conductor (paragraph 524.2). In applications (e.g. IT infrastructure) where the third
harmonic and odd multiples of third harmonic currents are higher than 33%, total
harmonic distortion, it may be necessary to increase the cross-sectional area of the
neutral conductor. In some cases the cross sectional area of the neutral conductor has
to be dimensioned on 1.45xIb of the line conductor.
The informative Annex G of the standard determines maximum Voltage drop values for
consumers’ installations. The voltage drop is defined as the voltage difference between
the origin of an electrical installation and any load point (see Table 1-16 for voltage
drop values for lighting and other uses)
This annex is informative so in fact not obligatory.
List of Acronyms
54
Table 1-16: Voltage drop values for lighting and other uses
The higher these voltage drop values the higher the energy losses in the cable (e.g. for
a resistive load a voltage drop of 5% is equal to an energy loss of 5%).
Annex I of the standard contains an overview of deviations and/or additional
requirements at member state level.
1.2.1.1.10 HD 361 S3:1999/A1:2006 System for cable designation
This Harmonisation Document details a designation system for harmonized power
cables and cords, of rated voltage up to and including 450/750 V. (see Table 1-17)
Table 1-17: Cable designation system
Symbol Relationship of Cable to Standards
H Cable conforming with harmonised standards
A Recognised National Type of cable listed in the relevant Supplement to harmonised standards
Symbol Value, Uo/U
01 =100/100V; (<300/300V)
03 300/300V
05 300/500V
07 450/750V
Part 2 of the Designation
Symbol Insulating Material
B Ethylene-propylene rubber
G Ethylene-vinyl-acetate
J Glass-fibre braid
M Mineral
N Polychloroprene (or equivalent material)
55
N2 Special polychloroprene compound for covering of welding cables according to HD 22.6
N4 Chlorosulfonated polyethylene or chlorinated polyethylene
N8 Special water resistant polychloroprene compound
Q Polyurethane
Q4 Polyamide
R Ordinary ethylene propylene rubber or equivalent synthetic elastomer for a continuous operating temperature of 60ºC
S Silicone rubber
T Textile braid, impregnated or not, on assembled cores
T6 Textile braid, impregnated or not, on individual cores of a multi-core cable
V Ordinary PVC
V2 PVC compound for a continuous operating temperature of 90ºC
V3 PVC compound for cables installed at low temperature
V4 Cross-linked PVC
V5 Special oil resistant PVC compound
Z Polyolefin-based cross-linked compound having low level of emission of corrosive gases and which is suitable for use in cables which, when burned, have low emission of smoke
Z1 Polyolefin-based thermoplastic compound having low level of emission of corrosive gases and which is suitable for use in cables which, when burned, have low emission of smoke
Symbol Sheath, concentric conductors and screens
C Concentric copper conductor
C4 Copper screen as braid over the assembled cores
Symbol Sheath, concentric conductors and screens
D Strain-bearing element consisting of one or more textile components, placed at the centre of a round cable or tributed inside a flat cable
D5 Central heart (non strain-bearing for lift cables only)
D9 Strain-bearing element consisting of one or more metallic components, placed at the centre of a round cable or distributed inside a flat cable
Symbol Special construction
No Symbol Circular construction of cable
H Flat construction of “divisible” cables and cores, either sheathed or non-sheathed
H2 Flat construction of “non-divisible” cables and cores
H6 Flat cable having three or more cores, according to DH 359 or EN 50214
H7 Cable having a double layer insulation applied by extrusion
H8 Extensible lead
Symbol Conductor material
No Symbol Copper
-A Aluminium
List of Acronyms
56
Symbol Conductor form
-D Flexible conductor for use in arc welding cables to HD 22Part 6 (flexibility different from Class 5 of HD 383)
-E Highly flexible conductor for use in arc welding cables to HD22 Part 6 (flexibility different from Class 6 of HD 383)
-F Flexible conductor of a flexible cable or cord (flexibility according to Class 5 of HD 383)
-H Highly flexible conductor of a flexible cable or cord (flexibility according to Class 6 of HD 383)
-K Flexible conductor of a cable for fixed installations (unless otherwise specified, flexibility according to Class 5 of HD 383)
-R Rigid, round conductor, stranded
-U Rigid round conductor, solid
-Y Tinsel conductor
Part 3 of the Designation
Symbol Number and size of conductors
(number) Number, n of cores
X Times, where a green/yellow core is not included
G Times, when a green/yellow core is included
(number) Nominal cross-section, s, of conductor in mm²
Y For a tinsel conductor where the cross-section is not specified
NOTE The use of the system for Recognised National Types of cable or cord has been
withdrawn by CENELEC TC 20. For non-harmonised cables of rated voltage up to and
including 450/750 V, National Committees are permitted to use any designation that
does not conflict with this HD.
The designation codes of these National normalized cables are defined in national
standards, e.g. in Germany according to DIN VDE xxxx, in France according to UTE NF
Cxxxx, in Belgium according to NBN xxxx, etc...
1.2.1.1.11 TR 50480 Determination of cross-sectional area of conductors and
selection of protective devices
This Technical Report applies to low-voltage installations with a nominal system
frequency of 50 Hz in which the circuits consist of insulated conductors, cables or
busbar trunking systems. It defines the different parameters used for the calculation of
the characteristics of electrical wiring systems in order to comply with rules of HD
384/HD 60364.
Remarks:
1. This Technical Report is also applicable for checking the compliance of the
results of calculations performed by software programs for calculation of cross-
sectional area of insulated conductors, cross-sectional area of cables and
characteristics for selection of busbar trunking systems with HD 384/HD 60364.
2. Effects of harmonics currents are not covered by this document.
57
3. The NORMAPME User Guide for European SME’s on CENELEC TR 50480 describes
the design procedure for an electric circuit. The procedure is summarized in the
flow diagram below:
Figure 1-11: Design procedure for an electric circuit
1.2.1.1.12 IEC 60287-1-1 Electric cables – Calculation of the current rating –Part 1-
1: Current rating equations (100 % load factor) and calculation of losses –
General
Applicable to the conditions of steady-state operation of cables at all alternating
voltages, and direct voltages up to 5 kV, buried directly in the ground, in ducts, troughs
or in steel pipes, both with and without partial drying-out of the soil, as well as cables
in air. The term "steady state" is intended to mean a continuous constant current
(100 % load factor) just sufficient to produce asymptotically the maximum conductor
temperature, the surrounding ambient conditions being assumed constant. The
standard provides formulae for current ratings and losses. The formulae given are
1. Determine electrical supply parameters
2. Calculate load current (Ib)
3. Select overcurrent device(s) In>Ib
4. Select cable type & cross sectional area
5. Check disconnection times in the event
of a fault to earth (shock protection)
6. Check thermal stress to the cable in the event of a short circuit (s²k²>I²t)
7. Calculate the voltage drop
List of Acronyms
58
essentially literal and designedly leave open the selection of certain important
parameters. These may be divided into three groups:
parameters related to construction of a cable (for example, thermal resistivity of
insulating material) for which representative values have been selected based
on published work;
parameters related to the surrounding conditions, which may vary widely, the
selection of which depends on the country in which the cables are used or are to
be used;
parameters which result from an agreement between manufacturer and user
and which involve a margin for security of service (for example, maximum
conductor temperature).
1.2.1.1.13 IEC 60287-3-2 Electric cables - Calculation of the current rating - Part 3-
2: Sections on operating conditions - Economic optimization of power cable
size
IEC 60287-3-2:2012 sets out a method for the selection of a cable size taking into
account the initial investments and the future costs of energy losses during the
anticipated operational life of the cable. Matters such as maintenance, energy losses in
forced cooling systems and time of day energy costs have not been included in this
standard.
For energy efficiency purpose, the most relevant element of the electrical installation is
the fixed wiring. The international standard wire sizes are given in the IEC 60228
standard of the International Electro technical Commission.
One important impact on wire size selection for installations comes from the so-called
electrical code. In European countries, an attempt has been made to harmonize
national wiring standards in an IEC standard, IEC 60364 Electrical Installations for
Buildings. Hence national standards follow an identical system of sections and chapters.
However, this standard is not written in such language that it can readily be adopted as
a national wiring code. As a result many European countries have their own national
wiring regulations and/or electrical installation codes, e.g. AREI (Belgium), NFC 15-100
(France), VDE-100 (Germany), BS 7671 (UK), NN1010 (the Netherlands),CEI 64-8
(Italy), etc.
These national regulations can be different from the international and European
standards. This means that wiring typology and acronyms are different from country to
country as well as the complementary electrical installation code. They have an
important impact on cable losses and as requested, an overview of the IEC, European
and national standards will be worked out and differences between these standards will
briefly be explained in this chapter.
TBC
1.2.1.2 Comparative analysis of existing test standards (if applicable)
EN 50395:2005 Electrical test methods for low voltage energy cables
EN 50395 contains electrical test methods required for the testing of harmonized low
voltage energy cables, especially those rated at up to and including 450/750 V.
59
NOTE 1 A description of the origin of these test methods and the background to this
European Standard is given in the Introduction and in Annex B. The particular cable
standard dictates the tests which need to be performed on the relevant cable type. It
also specifies whether the specific test is a type test (T), a sample test (S) or a routine
test (R) for the particular cable type.
NOTE 2 T, S and R are defined in the relevant cable standard. The requirements to be
met during or after the test are specified for the particular cable type in the relevant
cable standard. However, some test requirements are obvious and universal, such as
the fact that no breakdown shall occur during voltage tests, and these are stated in the
particular test method. Test methods for use specifically in utility power cables are not
covered by this European Standard. They can be found in HD 605. Test methods for
use specifically in communications cables are the responsibility of the Technical
Committee CENELEC TC 46X, Communication cables. At present such test methods are
given in EN 50289 series.
Remarks:
Reference is made to Annex A of EN 60228 for testing the electrical d.c.
resistance of conductor (see paragraph 5).
IEC 60468: “Method of measurement of resistivity of metallic materials” defines
a more detailed approach for determining the resistivity of solid metallic
conductors compared to the EN 60228 approach
IEC 60364-6: Low-voltage electrical installations – Verification
IEC 60364-6 provides requirements for initial verification, by inspection and testing, of
an electrical installation to determine, as far as reasonably practicable, whether the
requirements of the other parts of IEC 60364 have been met, and requirements for the
reporting of the results of the initial verification. The initial verification takes place upon
completion of a new installation or completion of additions or of alterations to existing
installations.
This standard also provides requirements for periodic verification of an electrical
installation to determine, as far as reasonably practicable, whether the installation and
all its constituent equipment are in a satisfactory condition for use and requirements for
the reporting of the results of the periodic verification.
Stakeholders are invited to provide input, e.g. are there tolerance issues?
1.2.1.3 New standards under development
Stakeholders are invited to provide input
IEC 60364-8-1 / FprHD 60364-8-1: 2013: Low voltage electrical installation -
Part 8-1: Energy efficiency – DRAFT version
This part of IEC 60364 provides additional requirements, measures and
recommendations for the design, erection and verification of electrical installations
including local production and storage of energy for optimizing the overall efficient use
of electricity. It introduces requirements and recommendations for the design of an
electrical installation in the frame of an Energy Efficiency management approach in
order to get the best permanent like for like service for the lowest electrical energy
consumption and the most acceptable energy availability and economic balance. These
requirements and recommendations apply for new installations and modification of
existing installations. This standard is applicable to the electrical installation of a
building or system and does not apply to products.
List of Acronyms
60
Reduction of energy losses in wiring is one of the many design requirements that are
mentioned in this draft standard. These losses can be reduced by:
- Reducing the voltage drop in the wiring by reducing the losses in the wiring.
Reference is made to IEC 60364-5-52 for recommendation on the maximum
voltage drop;
- Increasing the cross sectional area of conductors. Reference is made to IEC
60287-3-2 for an Economic optimization of power cable size;
- Power factor correction to improve the power factor of the load circuit. This will
decrease the amount of reactive energy consumption in the cable;
- Reduction of harmonic currents at the load level reduces thermal losses in the
wiring.
IEC TR 62125 Environmental statement specific to IEC TC 20 – Electric cables
“Annex A.4 Considerations for use and end of life phase [...] 2) Has information been
given to the user on the fact that the choice of transmission/distribution voltage and
the conductor cross-section will seriously influence the current transmission losses?”
This TR might evolve into a standard in the years to come (Europa cable)
1.3 Existing legislation
1.3.1 Key methodological issues related to existing legislation
This task identifies and analyses the relevant legislation for the products. It is
subdivided in three parts:
Subtask 1 - Legislation and Agreements at European Union level
This section identifies and shortly describes the relevance for the product scope of any
relevant existing EU legislation, such as on resource use and environmental impact, EU
voluntary agreements and labels.
Subtask 2 - Legislation at Member State level
This section includes a comparative analysis of any relevant existing legislation at
Member State level, such as on resource use and environmental impact, voluntary
agreements and labels.
Subtask 3 - Third Country Legislation
This section includes a comparative analysis of any relevant existing legislation in third
countries, such as on resource use and environmental impact, voluntary agreements
and labels.
1.3.1.1 Legislation and Agreements at European Union level
In the regulation and electrical code for electrical wiring in force worldwide, cable sizing
is generally a function of the following factors:
Maximum voltage drop: this criterion is usually decisive when sizing long cables;
Maximum current in wiring (to avoid cable overheating): this criterion is
generally determinative when sizing short cables;
Temperature of the conductor;
Emergency or short circuit current rating capacity of the wire;
Installation mode.
61
Most of the above criteria were selected on the basis of safety reasons or proper
equipment operation concerns, rather than on the basis of an objective of energy loss
reduction. For instance, IEC 60364 has requirements for protection against overcurrent,
a minimum cable cross section requirement for mechanical strength and a maximum
voltage drop. This maximum voltage drop requirement varies according to the
ownership of wiring (private vs. public), the end usage (lighting vs. others) and the
length of the wire.
The following European directives might be related to the electrical installation/ energy
cables within the scope of this study:
Directive 89/336/EEC 'Electromagnetic compatibility': Energy cables shall
be considered as ’passive elements‘ in respect to emission of, and immunity to,
electromagnetic disturbances and are as such exempted. Note: Certain
accessories may be susceptible to electromagnetic interference ! (IEC 60076-1).
Directive 2002/95/EC: Restriction of Hazardous Substances in electrical
and electronic equipment: Cables in the scope of RoHS should be compliant
either at the due date of the EEE category they fall in, or in 2019 if not
dedicated to any EEE specific category. External cables placed on the market
separately that are not part of another electrical and electronic equipment (EEE)
must meet the material restrictions and will need their own Declaration of
Conformity and CE marking from the relevant date.. The directive is restricted to
categories for use with a voltage rating not exceeding 1 000 Volt for alternating
current. Cable manufacturers adhere to the European RoHS* directive for
electrical materials, and participate to recycle for copper and plastics
The Construction Products Regulation (EU) No 305/2011 (CPR) is
replacing the Construction Products Directive (EU) No 89/106/EEC (CPD) since
July 1, 2013. CE marking of cables regarding fire performance is mandatory
within the CPR and will be possible once all the necessary standards are issued
and endorsed by the EC. In order to perform CE-marking a so called harmonized
product standard is needed in addition to the test a classification standards. The
product standard describes the construction of cable families. The current
document is termed Fpr EN 50575: “Power, control and communication cables -
Cables for general applications in construction works subject to reaction to fire
requirements”.
According to CENELEC JWG M/443 an optimistic scenario would be that CE marking
can start by early 2015 and will be obligatory by early 2016 (assuming the
minimum default one year transition time)25
Directive 2006/95/EC 'Low voltage equipment': For the purposes of this
Directive, ’electrical equipment‘ means any equipment designed for use with a
voltage rating of between 50 and 1 000 V for alternating current (and between
75 and 1 500 V for direct current, other than the equipment and phenomena
listed in Annex II of the Directive). Please note that LVD is applicable to
independent low-voltage equipment placed on EU market which is also used in
installations, such as control circuits, protection relays, measuring and metering
devices, terminal strips, etc. " and thus must carry the CE label.
According to the EU-Commission's guide on the Low Votlage Directive (LVD
GUIDELINES ON THE APPLICATION OF DIRECTIVE 2006/95/EC, last modified
January 2012); cables (and in general wiring material) is in the scope of the LVD
and therefore, must be CE-marked. In addition to the CE-mark, cables will be
25 Status summary of cable reaction to fire regulations in Europe by SP Technical Research Institute of Sweden & SINTEF NBL Norwegian Fire Research Laboratory
List of Acronyms
62
marked with HAR to increase the tractability. See Annex II of the above
mentioned LVD guide.
Directive 98/37/EC on the approximation of the laws of the Member
States relating to machinery. The machinery directive is not applicable for
power cables as such but may be applicable on certain accessories in the
electrical installation. (TBC)
Directive 2002/96/EC on ‘Waste Electrical and Electronic
Equipment‘ (WEEE) is not applicable as power cables are not falling under the
categories set out in Annex IA of the directive. (TBC)
Directive 2010/31/EU: Energy Performance of Buildings Directive and is
a revision of Directive 2002/91/EC. Under this Directive, Member States must
establish and apply minimum energy performance requirements for new and
existing buildings, ensure the certification of building energy performance and
require the regular inspection of boilers and air conditioning systems in buildings.
Moreover, the Directive requires Member States to ensure that by 2021 all new
buildings are so-called 'nearly zero-energy buildings'. (TBC)
REACH is the Regulation on Registration, Evaluation, Authorisation and
Restriction of Chemicals. It entered into force on 1st June 2007. It streamlines
and improves the former legislative framework on chemicals of the European
Union (EU). This directive is applicable to all the chemical substances that are
manufactured and/or marketed in the EU
Stakeholders are invited to provide input
1.3.1.2 Legislation at Member State level
In general, the national wiring codes of the European countries (see Table 1-18) are
based on the IEC 60364 x-xx standards. Most of the European countries have
additional national wiring rules. Table 1-19 in Annex 1-A gives an overview of the
supply parameters and domestic installation practices from some European countries
(Austria, Belgium, Denmark, Germany, Italy, Norway, Spain and United Kingdom)
63
Table 1-18: EU 28 National wiring codes
Country National Wiring code
Austria ÖVE/ÖNORM E8001
Belgium A.R.E.I/R.G.I.E
Bulgaria
Croatia (EU28 2013)
Cyprus
Czech Republic
Denmark Staerkstrombekendtgorelsen 6
Estonia
Finland SFS 6000 (based on IEC 60364)
France NFC 15-100
Germany VDE 0100
Greece ELOT HD384
Italy IEC EN 64-8
Greece
Hungary
Ireland
Italy CEI 64-8
Latvia
Lithuania
Luxembourg
Malta
Netherlands NEN 1010
Poland
Portugal UNE 20460
Romania
Slovakia
Slovenia
Spain UNE 20460
Sweden SS4364661/ELSÄK-FS 1999:5
UK BS7671 16° Edition IEE Wiring Regulations
The designation codes of National normalized cables are defined in national standards,
e.g. in Germany according to DIN VDE xxxx, in Belgium according to NBN xxxx, etc.
Legislation on environmental aspects:
Environmental Product Declaration (EPD) (source: Europacable):
French decree (2013-1264): The Order related to environmental product declarations
for construction and decoration products intended for use in buildings was published in
Official Journal No. 0302 from December 29th 2013. It defines the content of
environmental declarations and the LCA methodologies and calculation rules applicable
(see www.codde.fr)
The Norwegian legislation on recycling and treatment of Waste (FOR-2004-06-01-930)
has a dedicated section for cables (Amendment 1 on Product groups for EE-products
and EE-waste – § 12 on cables and wires)
Stakeholders are invited to provide input
List of Acronyms
64
1.3.1.3 Third Country Legislation
Scope:
This section again looks at legislation and measures in Third Countries (extra-EU) that
have been indicated by stakeholders as being relevant for the product group.
IMPORTANT NOTICE ON THE DIFFERENCES IN INTERNATIONAL LINE VOLTAGE
STANDARDS:
All European and most African and Asian countries use a supply that is within 10% of
230 V at 50 Hz, whereas Japan, North America and some parts of South America use a
voltage between 100 and 127 V at 60 Hz.
A number of building energy guidelines, standards or codes go beyond the existing
electrical safety and operational requirements by adopting more stringent maximum
voltage drop requirements to limit circuit impedance and thereby wiring energy loss. In
North America, the “Energy Standard for Buildings Except Low-Rise Residential
Buildings” of the American Society of Heating, Refrigeration and Air-Conditioning
Engineers (ASHRAE/ IESNA 90.1), as well as the National Energy Code for Buildings of
Canada (NECB 2011) are two examples.
Stakeholders are invited to provide input
1.3.1.4 Voluntary initiatives
The ELEKTRO+ Initiative in Germany is designed to assist in the planning and
installation of electrical systems in flats and houses. It covers the following areas:
scope and complexity of the electrical installation,
safety,
comfort,
energy efficiency.
Awareness among building owners and renovators for safer and more energy
sustainable electrical installation has been in decline for years. Even in new houses
electrical systems are often inadequate for the size of the building and fail to meet
minimum standards. There is a shortage of switches, sockets, lighting points,
communication devices and electrical circuits.
In older buildings the situation is even more critical. There are approximately 10.6
million occupied housing units in Germany built before 1949. The majority of these still
use their original electrical systems which fall well below the needs of today’s residents.
The demands of modern household appliances push these old electrical installations to
their limits. Residents are often unaware of the dangers. This overloading is reflected
in the high incidence of household fires; 10 – 15% being caused by the smouldering of
electrical cables and through the use of defective appliances.
The inadequate provision of electrical power points in houses leads to the use of
multi-socket connectors and extension leads. This puts a permanent overload onto
the electrical circuits, considerably raising the risk of fire. By providing additional
socket-outlets and circuits the cables will be less loaded on average.
65
The service life of an electrical installation is 40 to 45 years, so the decision to fit an up
to date system, meeting modern standards, will have a beneficial effect on the quality
and value of the building.
For this reason the HEA – Fachgemeinschaft für effiziente Energieanwendung e.V. has
been working for decades on the standardisation of electrical systems and has
developed, on the basis of the minimum standard (DIN 18015), its own set of HEA
Electrical Installation Values.
In the interests of ensuring better consumer protection the HEA, together with the
Zentralverband Elektrotechnik- und Elektronikindustrie e.V. (ZVEI), founded the
ELEKTRO+ Iniative to inform building owners and renovators about planning standards.
The ELEKTRO+ Initiative presents the standards and directives on electrical
installation in houses and flats as readily accessible information for planners (architects,
consultant electrical engineers and electrical contractors). This information is also
designed to help building owners and home buyers to better understand and have a
greater say in the planning of their electrical systems.
The ELEKTRO+ Initiative provides objective information for these target groups on the
planning and installation of electrical systems both for new buildings and for
modernisation projects.
The Approved Cables Initiative in the UK was established in March 2010 to address
the issue of unsafe, non-approved and counterfeit cable entering the UK marketplace.
With industry and regulator support, the ACI is taking a proactive and hard hitting
approach to educate the electrical supply chain – from manufacturers to end users
through a comprehensive communication schedule of seminars, marketing material and
articles to national trade media.
The Product Environmental Profile (PEP) Eco passport (http://www.pep-
ecopassport.org/p-e-p-association): is an environmental identity card for
electrical and HVAC-R products. It allows the results of a Life Cycle Analysis to be
presented appropriately and in accordance with international standards (ISO14025,
14040 and 14044).
The PEP association consists of manufacturers, users, institutional and professional
associations. It is responsible for implementing the PEP Eco passport ®, which is
recognised as the benchmark for good practices in terms of environmental
communication
Some cables manufacturers provide tools to calculate the economic optimum
section based on the use conditions (Europacable)
Stakeholders are invited to provide input
List of Acronyms
66
67
ANNEX 1-A
Table 1-19: Supply parameters and domestic installation practices per country26
Country Austria Belgium Denmark Italy Norway Spain United Kingdom
1. Distribution system (of the supplier)
TN-C-S 3% TT
TN-C-S (earth not made
available ) A little IT, being replaced by TN
The most common
system is TT Except for
Copenhagen- TN-C-S
For large industrial
TN-S
Mainly TT (domestic) TN-C-S
TN-S for large industrial
IT hospitals
Most common: IT without distributed
neutral, New residential areas:
TN-C-S Some parts of the
country: TT without
distributed neutral
90% TT Generally TN-C-S with a little TT
2. Provision of earth by supplier
Yes for TN-C-S (In addition the
installation must have its own
earthing system)
No Installer must
provide, less than 30 (300mA RCD) If
greater than 30 100mA RCD
Not for domestic
No for TT Yes for TN-C-S and most IT and TT (In
addition the installer must set
up an earthing system)
Not for domestic or small commercial
Legislation requires the supplier to
provide an earth terminal unless it is
considered inappropriate
e.g. Building supplies, farms, domestic swimming pools
26 NORMAPME User Guide on CENELEC TR 50480
Annex 1-A
68
Country
Austria
Belgium
Denmark
Italy
Norway
Spain United
Kingdom
3. Installation system
Most TN-S TT
TT TT for domestic TN-C-S for
commercial/ind ustrial
TN-S for large industrial, where they own their
transformer-
station
TT for domestic TN-C-S for
commercial/industri al
TN-S for large industrial
Most common: IT (without N) In
some parts of the country:
TT (without N) Where a new supply
transformer is
established: TN-C-S
Most common TT (90%)
TN-C-S with a little TN- S and a little TT
4. Demand limits (supply capacity)
Domestic max 60 A Every supply must be able to
deliver 18kW
Own transformer for loads greater
than 125A
Domestic up to 80A fuse
Domestic 3kW,4,5kW,6kW or
10kW 1Phase+N 230V or
10kW 3Phase 400V Can go to 15kW for
3Phase+N 400V ; increasing in 1kW
steps to 30kW with increasing demand
charges
Domestic: Most common:
63 A circuit breaker, but this is no
absolute limit.
level 1 -3.3kW, level 2 - 5.5kW,
level 3 - 12kW min 15A max 63A
Domestic up to 100A
5. Supply Voltage
3 phase and neutral
400/230V , Tolerance +10%
-6%
3Phase 230V 3Phase+N 230V 3Phase+N 400V
(new installations 3P+N 400V)
3Phase +N 400/230 V
Tolerance +/- 10%
3 phase and neutral 400/230V ,
Legislation requires Tolerance +/-10%
Note: Italy the Voltage supply is still 220
/380V for effect of the law 105/1949
IT and TT 230 V TN-C-S 230/400 V Supplier declares limits e.g.= ± 10%
No legislation
3 Phase+N 230/400V Tolerance
+/- 10%
3 phase and neutral 400/230V , Legislation
requires Tolerance +10% -6%
69
Country
Austria
Belgium
Denmark
Italy
Norway
Spain United
Kingdom
6. Allowed voltage drop
legislation1% before meter,
3% in
installation (4%
for domestic
installations ) but
recommended 1.5%
Proper functioning
4% for all installations
Proper functioning 4%;
1,5% Mounting
column
2,5%
Legislation: Proper functioning
Standard: 3 % for lighting 5 % for others
Domestic 3% lighting
5% power Can be exceeded if total voltage drop
No legislation that is specific Proper functioning For
domestic installations
Internal circuit of flat from Xfmer less than 9.5%
7. Legislation
Building regulations have
electrical –specific IEC
60364
Not retrospective
Reg Gen for elec installations
Royal decree of 1981-specific req
for domestic
Building regulations have
electrical – specific IEC
60364
Not retrospective
CEI 64-8 ; 700 page doc
CEI 0-21
90 page doc
Legislation for electrical
installations is general.
The Standard is one way of complying. The
Standard includes a specific section for
dwellings.
Yes specific ref to standard see
Electrical rules for low voltage
RD 842/2002
General requirement in the Building regulations for
domestic electrical installations to be
safe.
8. Registration of electrical installer
Chamber of Commerce, DM37/08
Yes Yes for domestic work
Country
Austria
Belgium
Denmark
Italy
Norway
Spain United
Kingdom
Annex 1-A
70
Country
Austria
Belgium
Denmark
Italy
Norway
Spain United
Kingdom
9. Fault level Maximum at supply
Max 16kA assumed
Assumed to be 10kA max at distribution
board. In practice fault
levels less than 6kA
6kA at supply Predicted to be
3000A
Ik,max = 16 kA cos = 0,3
Assumed to be 6kA max
at distribution board
(It applies only to household)
Max 6kA for single phase
10kA three phase. 15kA three phase when there is no
main-switch on the power supplier
Most common less than 10 kA at the
distribution board. The supplier often declares maximum
16 kA and minimum 0.5 kA.
No max/min described in the
legislation
Max 6kA for single phase
10kA three phase
Supply authorities declare 16kA
In practice fault levels less than 6kA
10.Loop impedance Max at supply, (or min fault level)
Max domestic
Loop impedance at supply = 0,6Ω Typically 0.3 For TT Ra+Rb less than 100
All TT and Ik,min = 5 x
In cos = 1.
No limits
RE Idn≤50V
30mA RCD protection
No limits TT, limit 20+R Assumed to be 0.35Ω
for TN-C-S supplies 0.8 Ω for TN-S 20Ω+RA for TT
11. Sockets
Schuko Sockets DIN 49440 30mA RCD
protection
Except SELV and luminaries, must
have earth contact Max 8 per circuit
30mA RCD protection
Sockets must comply
with Regulation
107-2-D1 Schuko sockets
are not allowed. Only the Danish
and French/Belgian
systems are allowed
Italian standard 16/10A, Schuko in
offices , in kitchen and washing machine
Schuko Schuko Must comply with BS 1363 (13A shuttered)
or EN 60309-2
Rings are commonly used in all domestic and commercial properties, but radial circuits are
allowed and often used. 30mA RCD protection
71
Country
Austria
Belgium
Denmark
Italy
Norway
Spain United
Kingdom
12. Lighting circuits
Separate Lightning Circuits (2 required) Separate
Socket Outlet circuits
Two circuits required Class I luminaires not
required
to be connected with earth
not separated New Standard 64-8- V3 September 2011, Level 1,2,3,: Level 1
Separate Lightning Circuits Separate Socket
Outlet circuits Level 2
Separate Lightning Circuits (3 required)
Separate Socket Outlet circuits
Level 3 Separate Lightning
Circuits (more than 3 required with
automatic control) Separate Socket Outlet
circuits
Not separated Separate required, up to 30 per circuit
It is practice to have separate lighting, socket outlet and
heating circuits, but is not a
requirement of the standard.
13.
Mixed power and lighting circuits
Separated Allowed, outlets limited to 8
Allowed Not Allowed Allowed Allowed, but generally separated
14. Installation standard used
HD 60364 series Austrian
special: ÖVE/ÖNORM
E8001
IEC 60- 364 series or “Danish
special rules”
Italian standard CEI IEC 60364 series supplemented by
HD 60364/384
IEC 60364 series supplemented by HD
60364/384, published as BS 7671
Annex 1-A
72
Country Austria Belgium Denmark Italy Norway Spain United Kingdom
15. Earthing requirements
Earth electrode required even for TN systems
TN: 4.5m vertically
10m horizontal TT: RA ≤ 100Ω
.
i) Earth electrode
RA ≤ 100Ω
ii) 35 mm2Cu
electrode installed In foundations as a
loop ii) If RA≥30Ω
separate RCD (I∆n 30mA)
for lighting and for Each group of
16 sockets
Earth electrode is a requirement
for TT incl. protection by RCD in all installations.
(I∆n 30mA)
TT system No limits RE Idn≤50V
With RCD (I∆n 30mA)
Separate earth electrode required
for all systems.
Dwellings supplied
from IT and TT:
Mainly TT (domestic) Industrial TN
16. Design(circuit calculations
Not required Table for Ze:
Ze U 0
Ia
Ia is interrupted for the time there are set in table 3.
The project required more power to 6kW, size of more 400m2
and Special Environments
Has to verify and document protection
against:
Overload
Short circuit
Fault
Simple tables are used for domestic installations
specifying cable csa, protective device and
cable
length (to meet voltage drop, shock
and short circuit requirements.
17. Singular National Characteristi cs
For domestic I2≤Iz For dwellings:
I2 ≤ Iz
Ringed socket circuits are commonly used in all
domestic
and commercial properties, but radial
circuits are allowed and often used.
73
Country Austria Belgium Denmark Italy Norway Spain United Kingdom
18. Lighting circuit polarised
yes Yes
19.
Socket circuit polarised
Yes for wiring
Yes for socket terminals
Yes for wiring
Yes for socket terminals
Annex 1-B
74
ANNEX 1-B
Table 1-14 shows the maximum resistance of conductor at 20 °C according IEC
60228:2004 Table 1 Class 1 solid conductors for single-core and multicore cables.
Based on the values in Table 1-14 the losses in Watt per meter cables (at 20 °C) for
current rating of 0,5A till 100A are shown in Table 1-20, Table 1-21 and Table 1-22
respectively for plain circular annealed copper conductors, metal coated circular
annealed copper conductors and circular or shaped aluminium and aluminium alloy
conductors.
Notes:
the calculation of the losses (R.I²) in Table 1-20, Table 1-21 and Table 1-22 is
made for each section and current rating in the table based upon the values in
Table 1-14.The maximum current-carrying capacities are based on Table C.52.1
of IEC 60364-5-52 (Installation method E, XLPE insulation) for copper
conductors and on Table B.52.13 of the same standard (Installation method E,
XLPE insulation) for aluminium conductors.
in the calculation of losses in this paragraph the skin effect isn’t taken into
account. However, when applying a S+x strategy to cables with large diameters
(above 400 mm² CSA) this gradually becomes important.
The resistance of a cable increases with the temperature. This is not included in
the calculation of losses here. A S+x strategy will result in a lower conductor
temperature.
75
Table 1-20: Losses in W/m for LV cables of class 1: circular, annealed copper
conductors: plain
Circular, annealed copper conductors: plain
Current (A)
0.5 1 2 4 10 16 20 40 64 100
CSA (mm²)
0.5 0.009 0.036 0.144 0.576 - - - - - -
0.75 0.006125
0.0245 0.098 0.392 2.45 - - - - -
1 0.004525
0.0181 0.0724 0.2896 1.81 4.6336 - - - -
1.5 0.003025
0.0121 0.0484 0.1936 1.21 3.0976 4.84 - - -
2.5 0.001853
0.00741 0.02964 0.11856 0.741 1.89696 2.964 - - -
4 0.001153
0.00461 0.01844 0.07376 0.461 1.18016 1.844 7.376 - -
6 0.00077 0.00308 0.01232 0.04928 0.308 0.78848 1.232 4.928 - -
10 0.000458
0.00183 0.00732 0.02928 0.183 0.46848 0.732 2.928 7.49568 -
16 0.000288
0.00115 0.0046 0.0184 0.115 0.2944 0.46 1.84 4.7104 11.5
25 0.000182
0.000727
0.002908
0.011632
0.0727 0.186112
0.2908 1.1632 2.977792
7.27
35 0.000131
0.000524
0.002096
0.008384
0.0524 0.134144
0.2096 0.8384 2.146304
5.24
50 9.68E-05
0.000387
0.001548
0.006192
0.0387 0.099072
0.1548 0.6192 1.585152
3.87
70 0.000067
0.000268
0.001072
0.004288
0.0268 0.068608
0.1072 0.4288 1.097728
2.68
95 4.83E-05
0.000193
0.000772
0.003088
0.0193 0.049408
0.0772 0.3088 0.790528
1.93
120 3.83E-05
0.000153
0.000612
0.002448
0.0153 0.039168
0.0612 0.2448 0.626688
1.53
150 0.000031
0.000124
0.000496
0.001984
0.0124 0.031744
0.0496 0.1984 0.507904
1.24
185 2.53E-05
0.000101
0.000404
0.001616
0.0101 0.025856
0.0404 0.1616 0.413696
1.01
240 1.94E-05
7.75E-05 0.00031 0.00124 0.00775 0.01984 0.031 0.124 0.31744 0.775
300 1.55E-05
0.000062
0.000248
0.000992
0.0062 0.015872
0.0248 0.0992 0.253952
0.62
400 1.16E-05
4.65E-05 0.000186
0.000744
0.00465 0.011904
0.0186 0.0744 0.190464
0.465
500 - - - - - - - - - -
630 - - - - - - - - - -
800 - - - - - - - - - -
1000 - - - - - - - - - -
1200 - - - - - - - - - -
Annex 1-B
76
Table 1-21: Losses in W/m for LV cables of class 1: circular, annealed copper
conductors: metal-coated
Circular, annealed copper conductors: Metal-coated
Current (A)
0.5 1 2 4 10 16 20 40 64 100
CSA
(mm²)
0.5 0.009175
0.0367 0.1468 0.5872 - - - - - -
0.75 0.0062 0.0248 0.0992 0.3968 2.48 - - - - -
1 0.00455 0.0182 0.0728 0.2912 1.82 4.6592 - - - -
1.5 0.00305 0.0122 0.0488 0.1952 1.22 3.1232 4.88 - - -
2.5 0.00189 0.00756 0.03024 0.12096 0.756 1.93536 3.024 - - -
4 0.001175
0.0047 0.0188 0.0752 0.47 1.2032 1.88 7.52 - -
6 0.000778
0.00311 0.01244 0.04976 0.311 0.79616 1.244 4.976 - -
10 0.00046 0.00184 0.00736 0.02944 0.184 0.47104 0.736 2.944 7.53664 -
16 0.00029 0.00116 0.00464 0.01856 0.116 0.29696 0.464 1.856 4.75136 11.6
25 - - - - - - - - - -
35 - - - - - - - - - -
50 - - - - - - - - - -
70 - - - - - - - - - -
95 - - - - - - - - - -
120 - - - - - - - - - -
150 - - - - - - - - - -
185 - - - - - - - - - -
240 - - - - - - - - - -
300 - - - - - - - - - -
400 - - - - - - - - - -
500 - - - - - - - - - -
630 - - - - - - - - - -
800 - - - - - - - - - -
1000 - - - - - - - - - -
1200 - - - - - - - - - -
77
Table 1-22: Losses in W/m for LV cables of class 1: Aluminium and aluminium alloy
conductors, circular or shaped
Aluminium and aluminium alloy conductors, circular or shaped
Current (A)
0.5 1 2 4 10 16 20 40 64 100
CSA (mm²)
0.5 - - - - - - - - - -
0.75 - - - - - - - - - -
1 - - - - - - - - - -
1.5 - - - - - - - - - -
2.5 - - - - - - - - - -
4 - - - - - - - - - -
6 - - - - - - - - - -
10 0.00077 0.00308 0.01232 0.04928 0.308 0.78848 1.232 4.928 12.61568 -
16 0.000478 0.00191 0.00764 0.03056 0.191 0.48896 0.764 3.056 7.82336 -
25 0.0003 0.0012 0.0048 0.0192 0.12 0.3072 0.48 1.92 4.9152 12
35 0.000217 0.000868 0.003472 0.013888 0.0868 0.222208 0.3472 1.3888 3.555328 8.68
50 0.00016 0.000641 0.002564 0.010256 0.0641 0.164096 0.2564 1.0256 2.625536 6.41
70 0.000111 0.000443 0.001772 0.007088 0.0443 0.113408 0.1772 0.7088 1.814528 4.43
95 0.00008 0.00032 0.00128 0.00512 0.032 0.08192 0.128 0.512 1.31072 3.2
120 6.33E-05 0.000253 0.001012 0.004048 0.0253 0.064768 0.1012 0.4048 1.036288 2.53
150 5.15E-05 0.000206 0.000824 0.003296 0.0206 0.052736 0.0824 0.3296 0.843776 2.06
185 0.000041 0.000164 0.000656 0.002624 0.0164 0.041984 0.0656 0.2624 0.671744 1.64
240 3.13E-05 0.000125 0.0005 0.002 0.0125 0.032 0.05 0.2 0.512 1.25
300 0.000025 0.0001 0.0004 0.0016 0.01 0.0256 0.04 0.16 0.4096 1
400 1.95E-05 7.78E-05 0.000311 0.001245 0.00778 0.019917 0.03112 0.12448 0.318669 0.778
500 1.51E-05 6.05E-05 0.000242 0.000968 0.00605 0.015488 0.0242 0.0968 0.247808 0.605
630 1.17E-05 4.69E-05 0.000188 0.00075 0.00469 0.012006 0.01876 0.07504 0.192102 0.469
800 9.18E-06 3.67E-05 0.000147 0.000587 0.00367 0.009395 0.01468 0.05872 0.150323 0.367
1000 7.28E-06 2.91E-05 0.000116 0.000466 0.00291 0.00745 0.01164 0.04656 0.119194 0.291
1200 6.18E-06 2.47E-05 9.88E-05 0.000395 0.00247 0.006323 0.00988 0.03952 0.101171 0.247
The resistance of the cable and thus the losses in a circuit can be reduced by using
cables with a larger CSA. Table 1-23 shows the reduction in cable resistance when
replacing a cable with CSA S by a cable with CSA S+1. S+1 is one size up, S+2 two
sizes up and S+3 three sizes up. Table 1-24 shows the reduction in cable resistance
when replacing a cable with CSA S by a cable with CSA S+2. Table 1-25 shows the
reduction in cable resistance when replacing a cable with CSA S by a cable with CSA
S+3.
The resistance of the cable and thus the losses in a circuit can be reduced by using
cables with a larger CSA. Table 1-23 shows the reduction in cable resistance when
replacing a cable with CSA S by a cable with CSA S+1. S+1 is one size up, S+2 two
sizes up and S+3 three sizes up. Table shows the reduction in cable resistance when
replacing a cable with CSA S by a cable with CSA S+2. Table 1-25 shows the reduction
in cable resistance when replacing a cable with CSA S by a cable with CSA S+3.
Annex 1-B
78
Table 1-23: S+1 scenario
S+1 resistance reduction
Nominal cross-sectional area
Circular. annealed copper conductors
Aluminium and aluminium alloy
conductors. circular or shaped Plain Metal coated
mm²
0.5 32% 32% -
0.75 26% 27% -
1 33% 33% -
1.5 39% 38% -
2.5 38% 38% -
4 33% 34% -
6 41% 41% -
10 37% 37% -
16 37% - 38%
25 28% - 37%
35 26% - 28%
50 31% - 26%
70 28% - 31%
95 21% - 28%
120 19% - 21%
150 19% - 19%
185 23% - 20%
240 20% - 24%
300 25% - 20%
400 - - 22%
500 - - 22%
630 - - 22%
800 - - 22%
1000 - - 21%
1200 - - 15%
79
Table 1-24: S+2 scenario
S+2 resistance reduction
Nominal cross-sectional area
Circular. annealed copper conductors
Aluminium and aluminium alloy
conductors. circular or shaped Plain Metal coated
mm²
0.5 50% 50% -
0.75 51% 51% -
1 59% 58% -
1.5 62% 61% -
2.5 58% 59% -
4 60% 61% -
6 63% 63% -
10 60% - 61%
16 54% - 55%
25 47% - 47%
35 49% - 49%
50 50% - 50%
70 43% - 43%
95 36% - 36%
120 34% - 35%
150 38% - 39%
185 39% - 39%
240 40% - 38%
300 - - 40%
400 - - 40%
500 - - 39%
630 - - 38%
800 - - 33%
1000 - - -
1200 - - -
Annex 1-B
80
Table 1-25: S+3 scenario
S+3 resistance reduction
Nominal cross-sectional area
Circular, annealed copper conductors
Aluminium and aluminium alloy
conductors, circular or shaped Plain Metal coated
mm²
0.5 66% 67% -
0.75 70% 70% -
1 75% 74% -
1.5 75% 75% -
2.5 75% 76% -
4 75% 75% -
6 76% - -
10 71% - 72%
16 66% - 66%
25 63% - 63%
35 63% - 63%
50 60% - 61%
70 54% - 53%
95 48% - 49%
120 49% - 51%
150 50% - 51%
185 54% - 53%
240 - - 52%
300 - - 53%
400 - - 53%
500 - - 52%
630 - - 47%
800 - - -
1000 - - -
1200 - - -
Table 1-26 shows the minimum and maximum resistance reduction for the above
mentioned cables. For instance when all class 1 plain copper cables are replaced by
plain copper cables with one size up the cables losses will reduce by minimum 19% and
maximum 41%.
81
Table 1-26: S+x scenario overview
Circular, annealed copper conductors Aluminium and aluminium alloy conductors, circular or shaped
Plain Metal coated
Upsizing
strategy
Minimum
resistance
reduction
Maximum
resistance
reduction
Minimum
resistance
reduction
Maximum
resistance
reduction
Minimum
resistance
reduction
Maximum
resistance
reduction
S+1 19% 41% 27% 41% 15% 38%
S+2 34% 62% 50% 63% 33% 61%
S+3 48% 76% 67% 76% 47% 72%
Table 1-27: S+x scenario overview based upon CSA ratio
CSA resistance reduction based upon CSA ratio (S+x)/S
mm² S+1 S+2 S+3 S+4 S+5
0.5 33% 50% 67% 80% 88%
0.75 25% 50% 70% 81% 88%
1 33% 60% 75% 83% 90%
1.5 40% 63% 75% 85% 91%
2.5 38% 58% 75% 84% 90%
4 33% 60% 75% 84% 89%
6 40% 63% 76% 83% 88%
10 38% 60% 71% 80% 86%
16 36% 54% 68% 77% 83%
25 29% 50% 64% 74% 79%
35 30% 50% 63% 71% 77%
50 29% 47% 58% 67% 73%
70 26% 42% 53% 62% 71%
95 21% 37% 49% 60% 68%
120 20% 35% 50% 60% 70%
150 19% 38% 50% 63% 70%
185 23% 38% 54% 63% 71%
240 20% 40% 52% 62% 70%
300 25% 40% 52% 63% 70%
400 20% 37% 50% 60% 67%
500 21% 38% 50% 58%
630 21% 37% 48%
800 20% 33%
1000 17%
1200
Minimum 17% 33% 48% 58% 67%
Maximum 40% 63% 76% 85% 91%
Average 27% 47% 61% 71% 78%
Average for CSA 1,5 till CSA 10 38% 61% 74% 83% 89%
Average for CSA 1,5 till CSA 25 36% 58% 72% 81% 86%
Annex 1-B
82
Assuming cables of section 1.5 mm² till 10 mm² are used in residential houses, opting
for a S+1 upsizing strategy would on average reduce the power losses in the installed
cables by 38% and by 61 % for the S+2 strategy, by 74% for the S+3 strategy and so
on.
Table 1-28: Conductor volume increase based upon CSA ratio
CSA (S) volume increase based upon CSA ratio
mm² S+1 S+2 S+3 S+4 S+5
0.5 50% 100% 200% 400% 700%
0.75 33% 100% 233% 433% 700%
1 50% 150% 300% 500% 900%
1.5 67% 167% 300% 567% 967%
2.5 60% 140% 300% 540% 900%
4 50% 150% 300% 525% 775%
6 67% 167% 317% 483% 733%
10 60% 150% 250% 400% 600%
16 56% 119% 213% 338% 494%
25 40% 100% 180% 280% 380%
35 43% 100% 171% 243% 329%
50 40% 90% 140% 200% 270%
70 36% 71% 114% 164% 243%
95 26% 58% 95% 153% 216%
120 25% 54% 100% 150% 233%
150 23% 60% 100% 167% 233%
185 30% 62% 116% 170% 241%
240 25% 67% 108% 163% 233%
300 33% 67% 110% 167% 233%
400 25% 58% 100% 150% 200%
500 26% 60% 100% 140%
630 27% 59% 90%
800 25% 50%
1000 20%
1200
Minimum 20% 50% 90% 140% 200%
Maximum 67% 167% 317% 567% 967%
Average 39% 95% 178% 297% 467%
Average for CSA 1,5 till CSA 6 61% 156% 304% 529% 844%
Average for CSA 1,5 till CSA 25 57% 142% 266% 448% 693%
Average for CSA 10 till CSA 70 46% 105% 178% 271% 386%
83
Table 1-29: Loss reduction per conductor volume increase
CSA (S) loss reduction per volume increase
mm² S+1 S+2 S+3 S+4 S+5
0.5 67% 50% 33% 20% 13%
0.75 75% 50% 30% 19% 13%
1 67% 40% 25% 17% 10%
1.5 60% 38% 25% 15% 9%
2.5 63% 42% 25% 16% 10%
4 67% 40% 25% 16% 11%
6 60% 38% 24% 17% 12%
10 63% 40% 29% 20% 14%
16 64% 46% 32% 23% 17%
25 71% 50% 36% 26% 21%
35 70% 50% 37% 29% 23%
50 71% 53% 42% 33% 27%
70 74% 58% 47% 38% 29%
95 79% 63% 51% 40% 32%
120 80% 65% 50% 40% 30%
150 81% 63% 50% 38% 30%
185 77% 62% 46% 37% 29%
240 80% 60% 48% 38% 30%
300 75% 60% 48% 38% 30%
400 80% 63% 50% 40% 33%
500 79% 63% 50% 42%
630 79% 63% 53%
800 80% 67%
1000 83%
1200
Minimum 60% 38% 24% 15% 9%
Maximum 83% 67% 53% 42% 33%
Average 73% 53% 39% 29% 22%
Average for CSA 1,5 till CSA 6 62% 39% 25% 16% 11%
Average for CSA 1,5 till CSA 25 64% 42% 28% 19% 14%
Average for CSA 10 till CSA 70 69% 49% 37% 28% 22%
Annex 1-B
84
Reducing the total length of cable for a circuit
Because the physical location of appliances/loads for a particular installation is fixed,
the total length of cable needed in the electrical installation cannot be changed, unless
other installation techniques or topologies are used. For instance adding an extra circuit
level with additional circuit boards could reduce the total length of cable used in the
electrical installation and even shorten the average circuit length of the electrical
installation.
The goal is to keep the distances between the main loads and the switch boards (and
transformers) as close as possible to minimize energy losses in the electrical wiring.
This can be achieved with the “barycentre method”: The objective of this method is to
set up the transformer and switchboard at a location based on a relative weighting due
to the energy consumption of the loads so that the distance to a higher energy
consumption load is less than the distance of a lower energy consumption load (see
Informative Annex A of FprHD 60364-8-1).
Using a size up strategy combined with a higher circuit load (less circuits) could reduce
the total length of the cable in the circuit and the resistance per meter cable, but the
load (I) will increase.
Reducing the load per circuit
Peak current load profile – secondary PFP
The power losses are determined by the I² factor. Reducing the average current per
circuit will reduce the loss exponential. However, reducing the loss per circuit by
diminishing the average current per circuit will in fact reduce the average load per
circuit. As a result extra circuits have to be added to the installation to serve the same
load as before, resulting in larger installed cable lengths.
For instance all the loads of one circuit could be fed over two circuits instead of one.
The load (I) per circuit will be lower, but the total length of cable will increase.
Figure 1-12 example: two parallel circuits instead of one circuit
For instance the losses (R.I²) in Figure 1-12 for scenario with one circuit are 10².R =
100.R, where R is the resistance of the cable in the circuit. For the same load the losses
in the second scenario with two parallel circuits of the same length is 5².R + 5².R =
50.R. However, when splitting the load (multiple appliances) over two circuits the load
should be divided in such a way that appliances consuming simultaneously are split
R Load: 10A
R Load: 5A
R Load: 5A
85
over different circuits; otherwise the losses will remain the same. However, it is not
trivial to split loads over different circuits when the load profiles are complex or
unknown. Energy management systems in combination with smart plugs or smart
appliances (BNAT) could overcome this problem and reduce the peaks in a circuit.
Looking at the installation level this means that losses in an installation can be reduced
by balancing loads over different circuits based upon the degree of simultaneity of
these loads.
Note: jagged load profiles with a lot of temporary peak (accumulated) currents cause
higher losses than more peak shaved load profiles demanding the same amount of
energy. Adequate design of circuits and load distribution over the circuits or control
mechanisms in energy management systems (or energy management functions in
building management systems) in buildings reducing the total energy usage and the
peak currents (peak clipping) will therefore diminish the losses in the circuits.
